TORLON
Solvay Advanced Polymers, L.L.C.
4500 McGinnis Ferry Road
Alpharetta, GA 30005-3914
USA
Phone: +1.770.772.8200
+1.800.621.4557 (U.S. only)
Fax:
+1.770.772.8454
Solvay Advanced Polymers, L.L.C. and its affiliates have offices in
the Americas, Europe, and Asia. Please visit our website at
www.solvayadvancedpolymers.com to locate the office nearest to you.
Product and Technical Literature
To our actual knowledge, the information contained herein is accurate
as of the date of this document. However, neither Solvay Advanced
Polymers, L.L.C. nor any of its affiliates makes any warranty, express
or implied, or accepts any liability in connection with this information
or its use. This information is for use by technically skilled persons at
their own discretion and risk and does not relate to the use of this
product in combination with any other substance or any other
process. This is not a license under any patent or other proprietary
right. The user alone must finally determine suitability of any information or material for any contemplated use, the manner of use and
whether any patents are infringed.
Health and Safety Information
Material Safety Data Sheets (MSDS) for products of Solvay Advanced
Polymers are available upon request from your sales representative or
by writing to the address shown on this document. The appropriate
MSDS should be consulted before using any of our products.
TORLON is a registered trademark of Solvay Advanced Polymers, L.L.C.
T-50246
© 2003 Solvay Advanced Polymers, L.L.C. All rights reserved.
D 08/03
design
®
TORLON
Polyamide-imide
Design Guide
Aircraft Clip Nuts
Clip nuts made of TORLON resin won’t
scratch through the protective covering to bare
metal during installation or corrode during use.
This can significantly reduce the hours of labor
and costly procedures associated with
replacing corroded metal parts. They can
withstand torque loads in excess of 100
inch-pounds, yet have enough elongation to
clip easily into place.
Stock Shapes of TORLON Resin
TORLON® resins can be formed into stock
shapes useful for machining prototypes by
injection molding, compression molding, or
extrusion. Shapes as large as 36 inches ( 900
mm) in outside diameter by 6 inches (150 mm)
long weighing 120 pounds (54 kg) have been
made.
Check Balls for 4-Wheel-Drive
Vehicle Transmissions
The durability of high-torque automatic
transmissions was improved when Chrysler
product development engineers specified
Torlon® polyamide-imide resin for the check
balls. The resin was selected for multiple
variations of three- and four-speed
transmissions coupled to the Magnum Engine
product line. The check balls withstand system
pressures, and provide excellent sealing
surfaces without causing metal damage, and
without adverse reaction to transmission oil at
temperatures approaching 300°F.
Table of Contents
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Wear Resistance and Post-Cure . . . . . . . . . . . . . . . . . . . . . . 30
Bearing Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
®
TORLON High Performance Molding Polymers . . . . . . . . . . . . . 1
The High Performance TORLON Polymers . . . . . . . . . . . . . . . . 2
Physical Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Industry and Agency Approvals . . . . . . . . . . . . . . . . . . . 32
Structural Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Performance Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Material Efficiency—Specific Strength and Modulus . . . . . . . . 33
Geometry and Load Considerations . . . . . . . . . . . . . . . . . . . . . 34
Examples of Stress and Deflection Formula Application. . . . . 34
Example 1–Short-term loading. . . . . . . . . . . . . . . . . . . . . . 34
Example 2-Steady load . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Example 3-Cyclic load . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Stress Concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Maximum Working Stresses for TORLON Resins . . . . . . . . . . 36
Mechanical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Tensile and Flexural Strength at Temperature Extremes. . . . . . . . 6
Ultra High Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Tensile Properties Per ASTM Test Method D 638. . . . . . . . . . 7
Ultra Low Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Flexural Modulus – Stiffness at High Temperature. . . . . . . . . . 7
Stress-Strain Relationship . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Resistance To Cyclic Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Fatigue Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Impact Resistance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Fracture Toughness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Thermal Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Thermogravimetric Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 12
Effects of Prolonged Thermal Exposure . . . . . . . . . . . . . . . . . 12
UL Relative Thermal Index . . . . . . . . . . . . . . . . . . . . . . . . . 12
Retention of Properties After Thermal Aging . . . . . . . . . . . . . 12
Specific Heat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Thermal Conductivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Coefficients of Linear Thermal Expansion (CLTE) . . . . . . . . . 13
Creep Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Flammability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Oxygen Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
NBS Smoke Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Toxic Gas Emission Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Ignition Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
UL 94 Flammability Standard . . . . . . . . . . . . . . . . . . . . . . . . 17
Horizontal Burning Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
20 MM Vertical Burn Test . . . . . . . . . . . . . . . . . . . . . . . . . . 17
FAA Flammability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
UL 57 Electric Lighting Fixtures . . . . . . . . . . . . . . . . . . . . . . . 18
Performance in Various Environments . . . . . . . . . . . . . . . . . . . 19
Chemical Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Resistance To Automotive and Aviation Fluids. . . . . . . . . . . 20
Chemical Resistance Under Stress . . . . . . . . . . . . . . . . . . . . 20
Effects of Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Absorption Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Equilibrium Absorption at Constant Humidity . . . . . . . . . . . 21
Dimensional Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Restoration of Dimensions and Properties . . . . . . . . . . . . . 22
Changes in Mechanical and Electrical Properties . . . . . . . . 22
Constraints on Sudden High Temperature Exposure . . . . . . 23
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Weather-Ometer Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Resistance to Gamma Radiation . . . . . . . . . . . . . . . . . . . . . . 24
Electrical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
TORLON Polymers for Insulating . . . . . . . . . . . . . . . . . . . . . . 25
Service in Wear-Resistant Applications. . . . . . . . . . . . . . . . . . . 26
An Introduction to TORLON PAI Wear-Resistant Grades . . . . . 26
Bearing Design Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Wear Rate Relationship . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Calculating the Pressure and Velocity . . . . . . . . . . . . . . . . . 26
PV Limit Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Measuring Wear Resistance . . . . . . . . . . . . . . . . . . . . . . . . 27
TORLON Wear-Resistant Grades . . . . . . . . . . . . . . . . . . . . . . 27
Effect of Mating Surface on Wear Rate . . . . . . . . . . . . . . . . . 29
Lubricated Wear Resistance . . . . . . . . . . . . . . . . . . . . . . . . . 29
®
Designing with TORLON Resin . . . . . . . . . . . . . . . . . . . 37
Fabrication Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Injection Molding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Extrusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Compression Molding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Post-Curing TORLON Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Guidelines for Designing TORLON Parts . . . . . . . . . . . . . . . . . . 38
Wall Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Wall Transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Draft Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Cores . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Ribs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Bosses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Undercuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Molded-in inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Threads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Holes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Secondary Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Joining. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Mechanical Joining Techniques. . . . . . . . . . . . . . . . . . . . . . . 40
Snap-fit: Economical and Simple . . . . . . . . . . . . . . . . . . . . 40
Threaded Fasteners. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Self-tapping Screws. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Molded-in Inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Threaded Mechanical Inserts . . . . . . . . . . . . . . . . . . . . . . . 40
Molded-in Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Interference Fits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Ultrasonic Inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Other Mechanical Joining Techniques. . . . . . . . . . . . . . . . . 41
Bonding with Adhesives . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Adhesive Choice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
TORLON PAI Grade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Surface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Adhesive Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Curing Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Bond Strength of Various Adhesives . . . . . . . . . . . . . . . . . . 42
Bonding TORLON Parts to Metal . . . . . . . . . . . . . . . . . . . . . 43
Guidelines for Machining Parts Made From TORLON Resin. . . . 44
Machined Parts Should be Recured. . . . . . . . . . . . . . . . . . . 44
Technical Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
i
List of Tables
List of Figures
TORLON Engineering Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Grades and Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Typical Properties* – US Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Typical Properties* – SI Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Room Temperature Tensile Properties per ASTM D638 . . . . . . . . . . . . . . . . . 7
Properties of TORLON Molding Resins at -321°F (-196°C) . . . . . . . . . . . . . . . . . 7
Izod impact resistance of 1/8” (3.2 mm) bars . . . . . . . . . . . . . . . . . . . . . . . 10
Polyamide-Imide Balances Fracture Toughness and High Glass Transition
Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Relative Thermal Indices of TORLON Resins . . . . . . . . . . . . . . . . . . . . . . . . 12
TORLON 4203L
Retention of Properties After Thermal Aging . . . . . . . . . . . . . . . . . . . . . . 13
Specific Heat of TORLON Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Thermal Conductivity of TORLON Resins . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
CLTE for TORLON Resins and Selected Metals.* . . . . . . . . . . . . . . . . . . . . . 13
Oxygen Index, ASTM D2863 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
NBS Smoke Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
FAA Toxic Gas Emission Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
UL Criteria for Classifying Materials V-0, V-1, or V-2 . . . . . . . . . . . . . . . . . . 17
Vertical Flammability by Underwriters’ Laboratories (UL 94) . . . . . . . . . . . . 17
Ignition Properties of TORLON 4203L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
FAA Vertical Flammability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Electric Lighting Fixtures, Flammability Requirements, UL 57 . . . . . . . . . . . 18
Chemical Resistance of TORLON 4203L, 24 hr at 200°F (93°C). . . . . . . . . . . . . . . . 19
Property Retention After Immersion in Automotive Lubricating Fluids at
300°F (149°C). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Effect of FORD ATF after 1,500 hours at 302°F (150°C). . . . . . . . . . . . . . . . 20
Tensile Strength After Immersion in Aircraft Hydraulic Fluid . . . . . . . . . . . . 20
Property Change of TORLON 4203L at 2% absorbed water . . . . . . . . . . . . . 22
Important Electrical Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Electrical Properties of TORLON Resins . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Wear Factors and Wear Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Wear Characteristics of TORLON 4301 PAI Against Various Metals. . . . . . . . 29
Lubricated wear resistance of TORLON 4301 . . . . . . . . . . . . . . . . . . . . . . . 29
Specific Strength and Modulus of TORLON polymers and Selected Metals. . 33
Maximum Working Stresses for Injection Molded TORLON Resins . . . . . . . . 36
Wall Thickness/Insert O.D. Relationship. . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Strength of HeliCoil Inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Strength of TORLON Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Screw Holding Strength of Threads in TORLON PAI . . . . . . . . . . . . . . . . . . . 41
Shear Strength of TORLON PAI to TORLON PAI Bonds . . . . . . . . . . . . . . . . . 42
Shear Strength of TORLON PAI to Metal Bonds . . . . . . . . . . . . . . . . . . . . . . 43
Guidelines for Machining Parts Made From TORLON Resin . . . . . . . . . . . . . 44
Structure of Polyamide-imide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
TORLON Resins Have Outstanding Tensile Strengths . . . . . . . . . . . . . . . . . . . 6
Flexural Strengths of TORLON Resins Are High
Across a Broad Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Tensile Strengths of Reinforced TORLON Resins Surpass Competitive
Reinforced Resins at 400°F (204°C). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Flexural Strengths of Reinforced TORLON Resins Surpass Competitive
Reinforced Resins at 400°F (204°C). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Flexural Moduli of TORLON Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Flexural Moduli of Reinforced TORLON Grades are Superior to Competitive
Reinforced Resins at 400°F (204°C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Stress-Strain in Tension at 73°F (23°C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Stress-Strain Detail at 73°F (23°C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Stress-Strain in Tension for TORLON Resins at 275°F (135°C). . . . . . . . . . . . 8
Flexural Fatigue Strength of TORLON resins at 30Hz . . . . . . . . . . . . . . . . . . . 9
Tension/Tension Fatigue Strength of TORLON 7130 and 4203L, at 30Hz,
A ratio: 0.90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Tension/Tension Low Cycle Fatigue Strength of TORLON 7130, at 2Hz,
A ratio: 0.90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
High Temperature Flexural Fatigue Strength of TORLON Resins at 350°F
(177°C), 30Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Izod Impact Resistance of TORLON Resins vs. Competitive Materials. . . . . . 10
Compact Tension Specimen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Thermogravimetric Analysis of TORLON 4203L . . . . . . . . . . . . . . . . . . . . . . 12
TORLON Resins Retain Strength After Thermal Aging at 482°F (250°C) . . . . 13
TORLON 4203L Strain vs. Time at 73°F (23°C) . . . . . . . . . . . . . . . . . . . . . . 14
TORLON 4275 Strain vs. Time at 73°F (23°C) . . . . . . . . . . . . . . . . . . . . . . . 14
TORLON 4301 Strain vs. Time at 73°F (23°C) . . . . . . . . . . . . . . . . . . . . . . . 14
TORLON 5030 Strain vs. Time at 73°F (23°C) . . . . . . . . . . . . . . . . . . . . . . . 14
TORLON 7130 Strain vs. Time at 73°F (23°C) . . . . . . . . . . . . . . . . . . . . . . . 14
TORLON 4203L Strain vs. Time at 400°F (204°C) . . . . . . . . . . . . . . . . . . . . 15
TORLON 4275 Strain vs. Time at 400°F (204°C) . . . . . . . . . . . . . . . . . . . . . 15
TORLON 4301 Strain vs. Time at 400°F (204°C) . . . . . . . . . . . . . . . . . . . . . 15
TORLON 5030 Strain vs. Time at 400°F (204°C) . . . . . . . . . . . . . . . . . . . . . 15
TORLON 7130 Strain vs. Time at 400°F (204°C) . . . . . . . . . . . . . . . . . . . . . 15
Equilibrium Moisture Absorption vs. Relative Humidity. . . . . . . . . . . . . . . . . 21
Water Absorption of TORLON Polymers at 73°F (23°C), 50% RH . . . . . . . . . 21
Water Absorption of TORLON Polymers at 110°F (43°C), 90% RH . . . . . . . . 21
Dimensional Change of TORLON Polymers at 73°F (23°C), 50% RH. . . . . . . 22
Dimensional Change of TORLON Polymers at 110°F (43°C), 90% RH. . . . . . 22
Thermal Shock Temperature vs. Moisture Content of TORLON 4203L . . . . . 23
Thermal Shock Temperature vs. Exposure Time for TORLON 4203L. . . . . . . 23
The Elongation of TORLON 4203L is Essentially Constant after Exposure to
Simulated Weathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Change in Tensile Strength of TORLON 4203L With Exposure to Simulated
Weathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Properties Change of TORLON 4203L Due to Gamma Radiation. . . . . . . . . . 24
Thrust Washer Calculation Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Material wear rate is a function of the Pressure-Velocity (PV) product . . . . . 27
Thrust Washer Test Specimen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Extended Cure at 500°F (260°C) Improves Wear Resistance . . . . . . . . . . . . 30
Beam used in examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Stress Concentration Factor for Circular Stress Raiser
(elastic stress, axial tension) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Gradual Blending Between Different Wall Thicknesses . . . . . . . . . . . . . . . . 38
Draft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
ii
Introduction
®
TORLON High Performance
Molding Polymers
The high-strength grades perform more like metals at elevated
temperature, even under considerable stress.
For reliable performance at extremely high temperature and
stress, use TORLON polymers. Parts made of TORLON engineering polymers perform under conditions generally considered too severe for thermoplastics. That’s why parts for the
space shuttle, automotive transmissions, and many other critical components have been molded from TORLON polymers.
Across a wide range of industries — electrical and electronics;
business equipment; aerospace; transportation; process; and
heavy equipment — TORLON parts meet design challenges.
Some other engineering resins may perform at 500°F (260°C),
but TORLON polymers maintain superior strength at this
extreme temperature. Of the high-temperature plastics,
TORLON polymers have the advantage of being injection-moldable. That means exact replication and low unit cost, making
TORLON polymers the cost-effective solution to difficult design
problems.
This manual introduces the reader to the TORLON polymer
family. Numerous graphs and tables present the physical properties and load-bearing capabilities of TORLON polymers. A
discussion of design guidelines and secondary operations
focuses on the practical aspects of fabricating high-performance TORLON parts. Using this manual, the designer can
relate the characteristics of these exceptional resins to his own
specific needs.
These grades are ideally suited for repetitively-used precision
mechanical and load-bearing parts.
The inherent lubricity of TORLON polyamide-imide is enhanced
with additives in the wear-resistant grades. Moving parts made
of TORLON polymers provide dependable service in lubricated
and non-lubricated environments.
Table 1
TORLON Engineering Polymers
High Strength
Wear Resistant
4203L
4275
5030
4301
7130
4435
Only TORLON engineering polymers offer a combination of:
• performance from cryogenic to 500°F (260°C)
• outstanding mechanical strength
• easy fabrication
• low flammability and smoke generation
• fatigue strength
Solvay Advanced Polymers’ TORLON high performance polymer
is a polyamide-imide, with the general structure:
• impact strength
Figure 1
• wear resistance
Structure of Polyamide-imide
• low expansion coefficients
• excellent thermal stability
• resistance to aviation and automotive fluids.
O
H
N
Ar
N
O
O
n
The variety of applications requiring high temperature resistance, high strength, and the economies of injection-molding
has led to the commercialization of several TORLON grades,
which can be divided into two categories; the high-strength
grades and the wear-resistant grades.
TORLON PAI Design Guide
• creep resistance
–1–
The High Performance TORLON Polymers
TORLON polyamide-imide resins are injection-moldable thermoplastics that offer truly outstanding performance. The diversity of end-use applications has led to development of several
grades, each designed to maximize specific properties.
If your application requires a special modified grade, we can
compound TORLON polymers to your specifications.
This page describes the TORLON family and suggests general
application areas. For specific advice concerning a particular
application, please contact your Solvay Advanced Polymers
representative.
Table 2
Grades and Applications
TORLON
Grade
Nominal Composition
Description of Properties
Applications
TiO2
Best impact resistance, most elongation, and
good mold release and electrical properties.
Connectors, switches, relays, thrust washers,
spline liners, valve seats, check balls, poppets,
mechanical linkages, bushings, wear rings,
Insulators, cams, picker fingers, ball bearings,
rollers, and thermal insulators.
glass fiber
High stiffness, good retention of stiffness at
elevated temperature, very low creep, and
high strength.
Burn-in sockets, gears, valve plates, fairings,
tube clamps, impellers, rotors, housings,
back-up rings, terminal strips, insulators, and
brackets.
carbon fiber
Similar to 5030 but higher stiffness. Best
retention of stiffness at high temperature, best
fatigue resistance. Electrically conductive.
Metal replacement, housings, mechanical
linkages, gears, fasteners, spline liners, cargo
rollers, brackets, valves, labyrinth seals,
fairings, tube clamps, standoffs, impellers,
shrouds, potential use for EMI shielding.
4301
graphite powder
fluoropolymer
General purpose, high-performance,
low-friction, wear-resistant compound
exhibiting high compressive strength.
Bearings, thrust washers, wear pads, strips,
piston rings, seals, vanes, and valve seats.
4275
graphite powder
fluoropolymer
Similar to 4301 with better wear resistance at
high speeds.
Bearings, thrust washers, wear pads, strips,
piston rings, seals, vanes, and valve seats.
4435
graphite powder
fluoropolymer
other additives
Excellent wear resistance and low friction at
higher pressures and velocities (>50,000
ft-lb/in2-min)
Bobbins, vanes, thrust washers, seal rings,
and pistons
High strength
4203L
5030
30%
7130
30%
Wear Resistant
®
TORLON High Performance Molding Polymers
–2–
Solvay Advanced Polymers, L.L.C.
Physical Properties
High impact strength, exceptional mechanical strength, and
excellent retention of these properties in high temperature
environments characterize all TORLON resins.
At room temperature, the tensile and flexural strengths of
TORLON 4203L are about twice that of polycarbonate and
nylon. At 500°F (260°C), the tensile and flexural strengths of
TORLON 4203L are almost equal to that of these engineering
resins at room temperature. Superior physical properties are
retained after long-term exposure to elevated temperature.
These physical properties are typical of injection-molded,
post-cured test specimens.
Footnotes for Typical Property Tables on Pages 4 and 5.
(1) Tensile properties per ASTM D638 appear on Page 7.
(2) Note: The test methods used to obtain these data measure response to heat and
flame under controlled laboratory conditions and may not provide an accurate measure of the hazard under actual fire conditions.
* By this test, this grade is conductive. See discussion on page 25.
TORLON PAI Design Guide
–3–
The High Performance TORLON Polymers
Table 3
Typical Properties* – US Units
Properties
Mechanical
Tensile Strength(1)
-321°F
73°F
275°F
450°F
Tensile Elongation
-321°F
73°F
275°F
450°F
Tensile Modulus
73°F
Flexural Strength
-321°F
73°F
275°F
450°F
Flexural Modulus
-321°F
73°F
275°F
450°F
Compressive Strength
Compressive Modulus
Shear Strength
73°F
Izod Impact Strength ( 18 in)
notched
unnotched
Poisson’s Ratio
Thermal
Deflection Temperature
264 psi
Coefficient of Linear Thermal Expansion
Thermal Conductivity
Flammability(2), Underwriters’ Laboratories
Limiting oxygen index(2)
Electrical
Dielectric constant
103 Hz
106 Hz
Dissipation factor
103 Hz
106 Hz
Volume resistivity
Surface resistivity
Dielectric strength (0.040 in)
General
Density
Hardness, Rockwell E
Water absorption, 24 hour
ASTM Test
Method
Units
D1708
kpsi
D1708
4301
4275
4435
5030
7130
31.5
27.8
16.9
9.5
23.7
16.3
10.6
18.8
19.0
16.9
8.1
16.0
13.0
7.5
29.5
29.7
23.1
16.3
22.8
29.4
22.8
15.7
6
15
21
22
7
20
17
3
7
15
17
6
4
3
4
7
15
12
3
6
14
11
700
950
1,130
1,410
1,560
3,220
41.0
34.9
24.8
17.1
31.2
23.5
16.2
29.0
30.2
22.4
15.8
22.0
18.7
13.2
54.4
48.3
35.9
26.2
45.0
50.7
37.6
25.2
1,140
730
560
520
32.1
580
1,000
790
720
24.1
770
1,390
1,060
810
740
17.8
580
2,150
1,630
1,500
20.0
1,240
20.4
1,700
1,550
1,430
38.3
1,150
3,570
2,400
2,270
1,900
36.9
1,430
18.5
16.1
11.1
8.7
20.1
17.3
2.7
20.0
0.45
1.2
7.6
0.39
1.6
4.7
0.39
0.8
4.1
0.42
1.5
9.5
0.43
0.9
6.4
0.39
532
17
1.8
94 V-0
45
534
14
3.7
94 V-0
44
536
14
4.5
94 V-0
45
532
8
5.6
94 V-0
539
9
2.5
94 V-0
51
540
5
3.6
94 V-0
52
4.2
3.9
6.0
5.4
7.3
6.6
4.4
4.2
0.026
0.031
2 x 1017
5 x 1018
580
0.037
0.042
8 x 1015
8 x 1017
0.059
0.063
8 x 1015
4 x 1017
2 x 107
6 x 106
0.022
0.050
2 x 1017
1 x 1018
840
0.051
86
0.33
0.053
72
0.28
0.054
70
0.33
0.057
62
0.12
%
D1708
kpsi
D790
kpsi
D790
4203L
kpsi
D695
D695
D732
kpsi
kpsi
kpsi
D256
ft•lbs/in
D648
°F
D696
C177
ppm/°F
Btu in/hr ft 2°F
D2863
%
D150
D150
D257
D257
D149
ohm-cm
ohm
V/mil
D792
D785
D570
lb/in3
%
0.058
94
0.24
0.054
94
0.26
*Typical properties – Actual properties of individual batches will vary within specification limits.
Physical Properties
–4–
Solvay Advanced Polymers, L.L.C.
Table 4
Typical Properties* – SI Units
Properties
Mechanical
Tensile Strength(1)
-196°C
23°C
135°C
232°C
Tensile Elongation
-196°C
23°C
135°C
232°C
Tensile Modulus
23°C
Flexural Strength
-196°C
23°C
135°C
232°C
Flexural Modulus
-196°C
23°C
135°C
232°C
Compressive Strength
Compressive Modulus
Shear Strength
23°C
Izod Impact Strength (3.2 mm)
notched
unnotched
Poisson’s Ratio
Thermal
Deflection Temperature
1.82 MPa
Coefficient of Linear Thermal Expansion
Thermal Conductivity
Flammability(2), Underwriters’ Laboratories
Limiting Oxygen Index(2)
Electrical
Dielectric Constant
103 Hz
106 Hz
Dissipation Factor
103 Hz
106 Hz
Volume Resistivity
Surface Resistivity
Dielectric Strength (1 mm)
General
Density
Hardness, Rockwell E
Water Absorption, 24 hour
ASTM Test
Method
Units
D1708
MPa
D1708
4301
4275
4435
5030
7130
218
192
117
66
164
113
73
130
131
116
56
110
90
52
204
205
160
113
158
203
158
108
6
15
21
22
7
20
17
3
7
15
17
6
4
3
4
7
15
12
3
6
14
11
4.9
6.6
7.8
9.7
10.8
22.3
287
244
174
120
219
165
113
203
212
157
111
152
129
91
381
338
251
184
315
355
263
177
7.9
5.0
3.9
3.6
220
4.0
6.9
5.5
4.5
170
5.3
9.6
7.3
5.6
5.1
120
4.0
14.8
11.2
10.3
138
8.5
14.1
11.7
10.7
9.9
260
7.9
24.6
16.5
15.6
13.1
250
9.9
128
112
77
60
140
120
142
1062
0.45
63
404
0.39
84
250
0.39
43
219
0.42
79
504
0.43
47
340
0.39
278
30.6
0.26
94 V-0
45
279
25.2
0.54
94 V-0
44
280
25.2
0.65
94 V-0
45
278
14.4
0.80
94 V-0
282
16.2
0.37
94 V-0
51
282
9.0
0.53
94 V-0
52
4.2
3.9
6.0
5.4
7.3
6.6
4.4
4.2
0.026
0.031
2 x 1017
5 x 1018
23.6
0.037
0.042
8 x 1015
8 x 1017
0.059
0.063
8 x 1015
4 x 1017
2 x 107
6 x 106
0.022
0.050
2 x 1017
1 x 1018
32.6
1.42
86
0.33
1.46
72
0.28
1.51
70
0.33
1.59
62
0.12
%
D1708
GPa
D790
MPa
D790
4203L
GPa
D695
D695
D732
MPa
GPa
MPa
D256
J/m
D648
°C
D696
C177
UL94
D2863
ppm/°C
W/mK
%
D150
D150
D257
D257
D149
ohm-cm
ohm
kV/mm
D792
D785
D570
g/cm3
%
1.61
94
0.24
1.48
94
0.26
*Typical properties – Actual properties of individual batches will vary within specification limits.
TORLON PAI Design Guide
–5–
The High Performance TORLON Polymers
Performance Properties
Figure 3
The unrivaled properties of TORLON engineering polymers
meet the requirements of the most demanding applications.
Strength retention over a wide range of temperatures and sustained stress, low creep, flame resistance, outstanding electrical properties, and exceptional integrity in severe environments
place TORLON polyamide-imide in a class by itself among
engineering resins.
Flexural Strengths of TORLON Resins Are High
Across a Broad Temperature Range
Mechanical Properties
Tensile and Flexural Strength at Temperature Extremes
Ultra High Temperature
TORLON polyamide-imide can be used in applications previously considered too demanding for many other engineering
plastics because of its outstanding tensile and flexural strength
combined with retention of these properties in continuous service at temperatures in excess of 450°F (232°C).
Figure 4
Tensile Strengths of Reinforced TORLON Resins Surpass
Competitive Reinforced Resins at 400°F (204°C).
While many competitive resins can claim “excursions” up to
500°F (260°C), TORLON polymers function with integrity at
extremely high temperatures, as shown by Figures 2 and 3,
which demonstrate the exceptional retention of tensile and
flexural strength of TORLON resins at elevated temperatures.
20
Even at 400°F (204°C), the strengths in both tensile and flexural modes of TORLON engineering polymers are better than
other high performance engineering resins. Figures 4 and 5
compare reinforced TORLON polymers to other high performance reinforced resins.
120
15
100
80
10
60
40
5
20
0
Tensile Strength, MPa
Tensile Strength, kpsi
TORLON
0
7130
5030
PES
PEEK
PEI
PPS
Material
Figure 5
Figure 2
Flexural Strengths of Reinforced TORLON Resins Surpass
Competitive Reinforced Resins at 400°F (204°C)
TORLON Resins Have Outstanding Tensile Strengths
200
150
20
100
10
50
0
Flexural Strength, MPa
Flexural Strength, kpsi
TORLON
30
0
7130
5030
PES
PEEK
PEI
PPS
Material
Mechanical Properties
–6–
Solvay Advanced Polymers, L.L.C.
Tensile Properties Per ASTM Test Method D 638
Ultra Low Temperature
Tensile properties reported in the preceding section were
obtained in accordance with ASTM Test Method D 1708. Since
tensile properties are frequently measured using ASTM test
method D 638, TORLON polymers were also tested in accordance with this method. The data appear in Table 6.
At the other end of the temperature spectrum, TORLON polymers do not become brittle as do other resins. Table 5 shows
TORLON resins have excellent properties under cryogenic
conditions.
Table 6
Table 5
Room Temperature Tensile Properties per ASTM D638
Properties of TORLON Molding Resins at -321°F (-196°C)
TORLON grade
TORLON grade
Property
Units
4203L
4301
4275
4435
5030
7130
Property
Units
4203L
4275
7130
5030
Tensile
Strength,
kpsi
22.0
16.4
16.9
13.6
32.1
32.0
Tensile strength(1)
(MPa)
(152)
(113)
(117)
(94)
(221)
(221)
kpsi
(MPa)
31.5
(216)
18.8
(129)
22.8
(157)
29.5
(203)
%
7.6
3.3
2.6
1.0
2.3
1.5
6
3
3
4
kpsi
650
990
1,280
2,100
2,110
2,400
(GPa)
(4.5)
(6.8)
(8.8)
(14.5)
(14.6)
(16.5)
Elongation,
Tensile
modulus,
Elongation at break(1)
%
Flexural strength(2)
kpsi
(MPa)
41.0
(282)
29.0
(200)
45.0
(310)
54.4
(374)
Flexural modulus(2)
kpsi
(GPa)
1,140
(7.8)
1,390
(9.6)
3,570
(24.6)
2,040
(14.0)
(1) ASTM D 1708
(2) ASTM D 790
Flexural Modulus – Stiffness at High Temperature
TORLON polyamide-imide has high modulus, making it a good
replacement for metal where stiffness is crucial to performance. TORLON parts can provide equivalent stiffness at significantly lower weight. Excellent retention of part stiffness and
resistance to creep or cold flow is predicted from the high and
essentially constant modulus of TORLON resins, even at 450°F
(232°C), as shown in Figure 6. Unlike competitive materials,
which lose stiffness at higher temperatures, TORLON polymers
have high moduli at elevated temperatures, as Figure 7
demonstrates.
Figure 6
Flexural Moduli of TORLON Polymers
TORLON PAI Design Guide
–7–
Flexural Modulus – Stiffness at High Temperature
Figure 7
Figure 9
Flexural Moduli of Reinforced TORLON Grades are Superior
to Competitive Reinforced Resins at 400°F (204°C)
Stress-Strain Detail at 73°F (23°C)
1.5
10
1.0
5
0.5
0.0
Tensile Stress, kpsi
TORLON
2.0
Flexural Modulus, GPa
Flexural Modulus, Mpsi
15
15.0
5030
7130
PES
PEI
150
5030
100
4203L
50
10.0
5.0
0.0
0.0
0
4435
7130
20.0
0.2
0.4
0.6
0.8
Tensile Stress, MPa
25.0
2.5
0
1.0
Strain, %
PPS PEEK
Material
Figure 10
Stress-Strain in Tension for TORLON Resins at 275°F
(135°C)
16
7130
100
14
12
80
5030
10
60
8
6
40
4203L
4
20
Tensile Stress, MPa
TORLON polyamide-imide does not yield at room temperature,
therefore, strain at failure or rupture is recorded as the elongation. Figure 8 show the stress-strain relationship for TORLON
grades at room temperature. Figure 9 shows just the first 1%
strain – the nearly linear (“Hookean”) portion of the room temperature curve. Figure 10 shows the initial portion of
stress-strain curve measured at 275°F (135°C).
Tensile Stress, kpsi
Stress-Strain Relationship
2
0
0.00
0.25
0.50
0.75
0
1.00
Strain, %
Figure 8
Stress-Strain in Tension at 73°F (23°C)
30.0
200
5030
25.0
4203L
150
20.0
15.0
100
10.0
50
5.0
0.0
Tensile Stress, MPa
Tensile Stress, kpsi
7130
0
0
2
4
6
8
Strain, %
ASTM D 638 Type 1 specimen
Mechanical Properties
–8–
Solvay Advanced Polymers, L.L.C.
Figure 12
Resistance To Cyclic Stress
Tension/Tension Fatigue Strength of TORLON 7130 and
4203L, at 30Hz, A ratio: 0.90
The values obtained in fatigue testing are influenced by the
specimen and test method; therefore, the values should serve
as guidelines, not absolute values. TORLON parts resist cyclic
stress. TORLON 7130, a graphite-fiber-reinforced grade, has
exceptional fatigue strength, and is superior to competitive
engineering resins. Figure 11, the S-N curves for selected
TORLON grades, shows that even after 10,000,000 cycles,
TORLON polyamide-imide has excellent resistance to cyclical
stress in the flexural mode, and Figure 12 demonstrates the
integrity of TORLON 7130 under tension/tension cyclical stress.
At lower frequencies, the fatigue strength of TORLON 7130 is
even higher, as shown in Figure 13.
25
7130
150
20
15
100
4203L
10
50
5
4203L
7130
0
103
104
105
106
Maximum Stress, MPa
200
0
107
Cycles to Failure
Figure 13
Tension/Tension Low Cycle Fatigue Strength of TORLON
7130, at 2Hz, A ratio: 0.90
30
200
7130
25
150
20
15
100
10
50
5
0
103
104
105
106
Maximum Stress, MPa
S-N diagrams, showing maximum stress versus cycles to failure, are useful in predicting product life. The maximum stress
using the anticipated force, appropriate stress concentration
factors, and section modulus is determined. The maximum
stress is then compared to the fatigue strength S-N curve for
the applicable environment to determine the maximum cyclic
stress the material can be expected to withstand.
30
Maximum Stress, kpsi
When a material is stressed cyclically, failure will occur at
stress levels lower than the material’s ultimate strength. Resistance to failure under cyclical loading or vibration, called
fatigue strength, is an important design consideration. TORLON
engineering polymers offer excellent fatigue strength in both
the tensile mode and the very severe flexural mode, a form of
reverse bending.
Maximum Stress, kpsi
Fatigue Strength
0
107
Cycles to Failure
Figure 11
Flexural Fatigue Strength of TORLON resins at 30Hz
Maximum Stress, kpsi
7130
5030
12
80
10
4203L
8
4275
60
6
4
2
0
103
40
4203L
4275
5030
7130
20
104
105
106
Maximum Stress, MPa
100
14
0
107
Cycles to Failure
TORLON PAI Design Guide
–9–
Fatigue Strength
High Temperature Flexural Fatigue Strength of TORLON
Resins at 350°F (177°C), 30Hz
14
Izod Impact Resistance of TORLON Resins vs. Competitive
Materials
100
3
TORLON
150
2
100
1
50
Notched Izod, J/m
Figure 14
7130
Figure 15
Notched Izod, ft-lbs/in
Even at high temperature, TORLON polymers maintain strength
under cyclic stress. Flexural fatigue tests were run at 350°F
(177°C) on specimens preconditioned at that temperature. The
results, shown in Figure 14, suggest TORLON polymers are
suitable for applications requiring fatigue resistance at high
temperature.
4203L
Maximum Stress, MPa
Maximum Stress, kpsi
5030
12
80
10
60
8
6
4
2
40
4203L
5030
7130
0
103
20
104
105
0
0
4203L 5030
4275
PI
PPS
PEI
PEEK
Material
0
107
106
Cycles to Failure
Impact Resistance
TORLON resins absorb impact energy better than most
high-modulus plastics. In tests using the notched Izod method
(ASTM D256), TORLON resins give results superior to those of
other high-temperature resins (Figure 15). Table 7 summarizes
both notched and unnotched impact data for TORLON resins.
Table 7
Izod impact resistance of 1/8” (3.2 mm) bars
Notched
TORLON grade
Unnotched
ft•lb/in
J/m
ft•lb/in
J/m
4203L
2.7
142
20.0
1062
4301
1.2
63
7.6
404
4275
1.6
84
4.7
250
4435
0.8
42
4.1
220
5030
1.5
79
9.5
504
7130
0.9
47
6.4
340
Resistance To Cyclic Stress
– 10 –
Solvay Advanced Polymers, L.L.C.
Table 8
Fracture Toughness
Fracture toughness can be assessed by measuring the fracture
energy (Glc) of a polymer. The Naval Research Laboratory (NRL)
uses a compact tension specimen (Figure 16) to determine Glc
a measure of a polymer’s ability to absorb and dissipate impact
energy without fracturing — larger values correspond to higher
fracture toughness. Table 8 shows selected data from NRL
Memorandum Report 5231 (February 22,1984). As expected,
thermosetting polymers cannot absorb and dissipate impact
energy as well as thermoplastics and consequently have lower
fracture energies. TORLON polyamide-imide exhibits outstanding fracture toughness, with a Glc of 1.6 ft-lb/in2 (3.4 kJ/m2).
Glass transition temperatures (Tg) are included in the table to
indicate the tradeoff between fracture toughness and useful
temperature range. polyamide-imide is characterized by a balance of toughness and high Tg.
Polyamide-Imide Balances Fracture Toughness and
High Glass Transition Temperature
Fracture energy
Tg
ft•lb/in2
kJ/m2
°F
°C
Polyimide-1
0.095
0.20
662
350
Polyimide-2
0.057
0.12
680
360
Tetrafunctional epoxy
0.036
0.076
500
260
polyamide-imide
1.6
3.4
527
275
Polysulfone
1.5
3.1
345
174
Polyethersulfone
1.2
2.6
446
230
Thermosets
Thermoplastics
Polyimide-4
1.0
2.1
689
365
Polyimide-3
0.38
0.81
619
326
Polyphenylene sulfide
0.10
0.21
—
—
Figure 16
Compact Tension Specimen
a
b
W
2
GIC =
Y 2Pc a
EW 2 b 2
Where:
Y = 29.6 - 186 (a/w) + 656 (a/w)2 - 1017 (a/w)3 + 639 (a/w)4
P = critical fracture load
a = crack length
E = sample modulus
c
TORLON PAI Design Guide
– 11 –
Fracture Toughness
Thermal Stability
Table 9
Relative Thermal Indices of TORLON Resins
Thermogravimetric Analysis
Mechanical
TORLON resins are exceptionally stable over a wide range of
temperatures. When heated at a rate of 18°F (10°C) per minute
in air or nitrogen atmospheres, TORLON 4203L shows virtually
no weight loss over its normal service temperatures and well
beyond, as shown in Figure 17.
Minimum
thickness
Electrical
in
mm
°F
°C
°F
°C
°F
°C
TORLON 4203L 0.031 0.81
428
220
*
*
410
210
Without
impact
0.047
1.2
428
220
*
*
410
210
0.096
2.4
428
220
*
*
410
210
0.118
3.0
428
220
392
200
428
220
TORLON 4301
0.118
3.0
*
*
392
200
392
200
TORLON 5030
0.062
1.5
428
220
*
*
*
*
0.096
2.4
428
220
*
*
*
*
0.118
3.0
428
220
392
200
428
220
Figure 17
Thermogravimetric Analysis of TORLON 4203L
With
impact
*not tested
The UL Relative Thermal Index predicts at least 100,000 hours
of useful life at the index temperature. TORLON polymers have
UL relative thermal indices as high as 220°C, which is equivalent to more than eleven years of continuous use at 428°F, and
is significantly higher than most high-temperature engineering
resins. Table 9 summarizes the relative thermal indices of
TORLON PAI grades 4203L, 4301, and 5030. Refer to Underwriters’ Laboratories website for the latest information,
www.ul.com.
Retention of Properties After Thermal Aging
TORLON polyamide-imide resists chemical breakdown and
retains high strength after prolonged thermal exposure. One
method for determining the thermal stability of polymers is to
measure mechanical properties of samples after aging at elevated temperatures.
Effects of Prolonged Thermal Exposure
UL Relative Thermal Index
The UL Relative Thermal Index provides an estimate of the
maximum continuous use temperature and is defined by the
method prescribed by Underwriters’ Laboratories.
Initial properties, including tensile strength, impact strength,
dielectric strength, arc resistance, dimensional stability, and
flammability, are determined for the test material. For each
property and each aging temperature, a record is kept of
elapsed time and the change in that property as a percent of
initial. The “end-of-life” for a property is the time required at
the aging temperature to reach 50 percent of initial. End-of-life
points are plotted and regression applied to predict “life expectancy” at any operating temperature. The Relative Thermal
Index is that temperature at which life expectancy is 100,000
hours. TORLON polymers were tested in accordance with the
above procedure for 50 percent degradation of dielectric
strength (Electrical), lzod impact (Mechanical-with impact), and
tensile strength (Mechanical-without impact). The other properties did not change significantly.
Thermal Stability
– 12 –
Injection molded and post-cured tensile bars (ASTM D1708
configuration, 1 8 inch thick) were aged in forced air ovens at
482°F (250°C). Specimens were periodically removed from the
ovens, conditioned at 73°F (23°C) and 50 percent relative
humidity then tested for tensile strength.
TORLON resins retain strength after long-term aging at high
temperature, as shown in Figure 18. After 10,000 hours, tensile
strengths of TORLON polymers exceed the ultimate strength of
many competitive resins. TORLON 4203L, for example, still has
tensile strength of over 25,000 psi. It is interesting to note that
the specimens actually increase in tensile strength initially,
because even greater strength is attained beyond the standard
post cure.
TORLON polymers maintain exceptional electrical and mechanical properties and UL flammability ratings after long-term heat
aging. Table 10 demonstrates that TORLON 4203L is still suitable for demanding applications even after extended exposure
to 482°F (250°C).
Solvay Advanced Polymers, L.L.C.
Figure 18
Thermal Conductivity
TORLON Resins Retain Strength After Thermal Aging at
482°F (250°C)
TORLON resins have low thermal conductivity, and are suitable
for applications requiring thermal isolation. TORLON heat
shields protect critical sealing elements from high temperatures, and protect sensitive instrument elements from heat
loss. Table 12 shows the thermal conductivity of TORLON resins measured using ASTM C177 with 0.06 in. (1.6 mm) thick
specimens and a cold plate temperature of 122°F (50°C) and a
hot plate temperature of 212°F (100°C).
35
25
200
4203L
150
20
4301
15
10
5
0
100
100
5030
4301
4203L
200 300
50
500
1000
2000 3000 5000
Tensile Strength, MPa
Tensile Strength, kpsi
5030
30
Table 12
Thermal Conductivity of TORLON Resins
0
10000
Aging Time, hours
Table 10
TORLON 4203L
Retention of Properties After Thermal Aging
Property
Dielectric strength*, V/mil (kV/mm)
Flammability**, UL 94
Dimensional change**, %
Tensile strength retained**, %
lzod impact strength retained**, %
Hours at 480°F (250°C)
2,000
12,000
17,000
654
94 V-0
94 V-0
94 V-0
0.0
0.5
0.9
110
86
67
101
67
38
TORLON
Grade
4203L
4301
4275
4435
5030
7130
Thermal conductivity
W/m•K
Btu•in/hr•ft2•°F
1.8
0.26
3.7
0.54
4.5
0.65
5.6
0.80
2.5
0.37
3.6
0.53
Coefficients of Linear Thermal Expansion (CLTE)
As shown in Table 13, the thermal expansion of filled TORLON
polyamide-imide nearly matches that of common metals.
*specimen thickness 0.035” (0.9 mm)
Table 13
**specimen thickness 0.125” (3.2 mm)
CLTE for TORLON Resins and Selected Metals.*
CLTE
Specific Heat
Specific heat as a function of temperature was determined
using a differential scanning calorimeter
The data for four TORLON grades at four temperatures are presented in Table 11.
Table 11
Specific Heat of TORLON Polymers
TORLON grade
Temperature, °F (°C)
77 (25)
212 (100)
392 (200)
482 (250)
TORLON PAI Design Guide
4203L
0.242
0.298
0.362
0.394
Specific Heat, cal/gm°C
4301
5030
0.240
0.298
0.359
0.385
0.229
0.276
0.327
0.353
7130
0.230
0.285
0.346
0.375
– 13 –
TORLON 7130
Inconel X, annealed
Plain carbon steel AISI-SAE 1020
Titanium 6-2-4-2
TORLON 5030
Copper
Stainless steel, type 304
Commercial bronze, 90%, C2200
Aluminum alloy 2017, annealed,
ASTM B221
TORLON 4275
TORLON 4301
Aluminum alloy 7075
TORLON 4203L
ppm/°F
5.0
6.7
6.7
7.0
9.0
9.3
9.6
10.2
ppm/°C
9.0
12.1
12.1
12.6
16.2
16.7
17.3
18.4
12.7
22.9
14.0
14.0
14.4
17.0
25.2
25.2
26.0
30.6
*The CLTE data for TORLON resins were determined per ASTM D 696, over a temperature range of 75-300°F (24-149”C). CLTE data for metals are from the CRC Handbook of Chemistry and Physics, 54th ed. and Materials Engineering, 1984 Materials
Selector edition, Dec. 1983.
Coefficients of Linear Thermal Expansion (CLTE)
Figure 21
A limitation of most plastics is deformation under stress, commonly called creep. TORLON polyamide-imide resists creep,
and handles stress more like a metal than a plastic. To get
measurable creep, TORLON polymer must be stressed beyond
the ultimate strength of most other plastics. The designer must
consider the long-term creep behavior of plastics under the
expected stress and temperature conditions of the proposed
application. Figures 19 through 23 summarize selected data
from tensile creep tests (ASTM D2990) at applied stresses of
5,000, 10,000, and 15,000 psi (34.5, 68.9, and 103.4 MPa) at
room temperature.
TORLON 4301 Strain vs. Time at 73°F (23°C)
5
5 kpsi (34.5 MPa)
10 kpsi (68.9 MPa)
15 kpsi (103.4 MPa)
4
Strain, %
Creep Resistance
3
2
1
0
1
10
100
1000
Time, hours
Figure 19
Figure 22
TORLON 4203L Strain vs. Time at 73°F (23°C)
TORLON 5030 Strain vs. Time at 73°F (23°C)
5
5
5 kpsi (34.5 MPa)
10 kpsi (68.9 MPa)
15 kpsi (103.4 MPa)
4
Strain, %
Strain, %
4
5 kpsi (34.5 MPa)
10 kpsi (68.9 MPa)
15 kpsi (103.4 MPa)
3
2
3
2
1
1
0
0
1
10
100
1
1000
10
100
Figure 20
Figure 23
TORLON 4275 Strain vs. Time at 73°F (23°C)
TORLON 7130 Strain vs. Time at 73°F (23°C)
5
5
5 kpsi (34.5 MPa)
10 kpsi (68.9 MPa)
15 kpsi (103.4 MPa)
5 kpsi (34.5 MPa)
10 kpsi (68.9 MPa)
15 kpsi (103.4 MPa)
4
Strain, %
4
Strain, %
1000
Time, hours
Time, hours
3
2
3
2
1
1
0
0
1
10
100
1
1000
100
1000
Time, hours
Time, hours
Thermal Stability
10
– 14 –
Solvay Advanced Polymers, L.L.C.
Figure 26
Figures 24 through 28 show this data for tests performed at
400°F (204°C).
TORLON 4301 Strain vs. Time at 400°F (204°C)
Non-reinforced TORLON grades may creep or rupture at
extremely high temperatures – over 400°F (204°C) – when
stress exceeds 5,000 psi (34.5 MPa). For these applications, a
reinforced grade is recommended.
5
5 kpsi (34.5 MPa)
Strain, %
4
3
2
1
0
1
10
100
1000
Time, hours
Figure 24
Figure 27
TORLON 4203L Strain vs. Time at 400°F (204°C)
TORLON 5030 Strain vs. Time at 400°F (204°C)
5
5
5 kpsi (34.5 MPa)
10 kpsi (68.9 MPa)
5 kpsi (34.5 MPa)
4
Strain, %
Strain, %
4
3
2
3
2
1
1
0
0
1
10
100
1000
1
10
Time, hours
100
1000
Time, hours
Figure 25
Figure 28
TORLON 4275 Strain vs. Time at 400°F (204°C)
TORLON 7130 Strain vs. Time at 400°F (204°C)
5
5
5 kpsi (34.5 MPa)
5 kpsi (34.5 MPa)
10 kpsi (68.9 MPa)
4
Strain, %
Strain, %
4
3
2
1
3
2
1
0
0
1
10
100
1000
1
Time, hours
TORLON PAI Design Guide
10
100
1000
Time, hours
– 15–
Creep Resistance
Flammability
Table 15
NBS Smoke Density
Test data indicate the suitability of TORLON parts for electrical,
electronic, aerospace, and other applications where
flammability is of great concern. TORLON 5030 and 7130
exceed FAA requirements for flammability, smoke density, and
toxic gas emission, and surpass, by a large margin, the proposed requirements for aircraft interior use.
Oxygen Index
The oxygen index is defined by ASTM D 2863 as the minimum
concentration of oxygen, expressed as volume percent, in a
mixture of oxygen and nitrogen that will support flaming combustion of a material initially at room temperature under the
conditions of this method.
Since ordinary air contains roughly 21 percent oxygen, a material whose oxygen index is appreciably higher than 21 is considered flame resistant because it will only burn in an oxygen-enriched atmosphere. The oxygen indices of several
TORLON resins are shown in Table 14. The high values indicate
a high degree of combustion resistance.
NFPA 258. Specimen thickness 0.05-0.06 inch (1.3-1.5 mm)
Sm= Smoldering, Fl = Flaming
TORLON
4203L
Sm
TORLON
5030
Fl
Sm
TORLON
7130
Fl
Sm
Fl
Minimum light
transmittance ™, %
92
6
96
56
95
28
Maximum specific
optical density (Dm)
5
170
2
35
3
75
18.5
18.6
10.7
15.7
17.0
16.0
Time to 90% Dm,
minutes
Toxic Gas Emission Test
Table 16
FAA Toxic Gas Emission Test
National Bureau of Standards, NFPA 258
Specimen thickness 0.05-0.06 inch (1.3-1.5 mm)
Table 14
Sm= Smoldering, Fl = Flaming
Oxygen Index, ASTM D2863
TORLON Grade
TORLON 5030
Oxygen Index, %
TORLON 7130
Sm
ppm
Fl
ppm
Sm
ppm
Fl
ppm
4203L
45
4301
44
Hydrochloric acid
0
<1
0
<1
4275
45
Hydrofluoric acid
0
0
0
0
5030
51
Carbon monoxide
<10
120
<10
100
7130
52
Nitrogen oxides
<2
19
0
14
Hydrocyanic acid
0
4
0
5
NBS Smoke Density
Sulfur dioxide
0
0
0
4
When a material burns, smoke is generated. The quantity and
density of the generated smoke is important in many
applications.
Ignition Properties
ASTM test method E 662 provides a standard technique for
evaluating relative smoke density. This test was originally
developed by the National Bureau of Standards (NBS), and is
often referred to as the NBS Smoke Density test.
The ignition properties of TORLON 4203L resin were measured
using ASTM Test Method D 1929 and the results are shown in
Table 17.
Flash ignition temperature is defined as the lowest temperature
of air passing around the specimen at which a sufficient
amount of combustible gas is evolved to be ignited by a small
external pilot flame.
TORLON resins were tested using both the smoldering and
flaming modes. The results are shown in Table 15.
Self-ignition temperature is defined as the lowest temperature
of air passing around the specimen at which, in the absence of
an ignition source, the self-heating properties of the specimen
lead to ignition or ignition occurs of itself, as indicated by an
explosion, flame, or sustained glow.
Flammability
– 16 –
Solvay Advanced Polymers, L.L.C.
These values can be used to rank materials according to their
ignition susceptibility.
Table 17
Ignition Properties of TORLON 4203L
ASTM D1929
°F
°C
Flash ignition temperature
1058°F
570°C
Self ignition temperature
1148°F
620°C
The 20 MM Vertical Burn Test is more aggressive than the
94HB test and is performed on samples that measure 125 mm
in length, 13 mm in width, and the minimum thickness at
which the rating is desired (typically 0.8 mm or 1.57 mm).
The samples are clamped in a vertical position with a
20-mm-high blue flame applied to the lower edge of the
clamped specimen. The flame is applied for 10 seconds and
removed. When the specimen stops burning, the flame is reapplied for an additional 10 seconds and then removed. A total of
five bars are tested in this manner. Table 18 lists the criteria by
which a material is classified in this test.
UL 94 Flammability Standard
The UL 94 flammability standard established by Underwriters’
Laboratories is a system by which plastic materials can be
classified with respect to their ability to withstand combustion.
The flammability rating given to a plastic material is dependent
upon the response of the material to heat and flame under controlled laboratory conditions and serves as a preliminary indicator of its acceptability with respect to flammability for a particular application. The actual response to heat and flame of a
thermoplastic depends on other factors such as the size, form,
and end-use of the product. Additionally, characteristics in
end-use application such as ease of ignition, burning rate,
flame spread, fuel contribution, intensity of burning, and products of combustion will affect the combustion response of the
material.
Three primary test methods comprise the UL 94 standard. They
are the Horizontal Burning Test, the 20 MM Vertical Burning
Test, and the 500 MW Vertical Burning Test.
Horizontal Burning Test
For a 94HB classification rating, injection molded test specimens are limited to a 5.0 in. (125 mm) length, 0.5 in. (13 mm)
width and the minimum thickness for which the rating is
desired. The samples are clamped in a horizontal position with
a 20-mm blue flame applied to the unclamped edge of the
specimen at a 45-degree angle for 30 seconds or so as soon
as the combustion front reaches a pre-marked line 25 mm
from the edge of the bar. After the flame is removed, the rate of
burn for the combustion front to travel from the 25-mm line to
a pre-marked 100-mm line is calculated. At least three specimens are tested in this manner. A plastic obtains a 94HB rating
by not exceeding a burn rate of 40 mm/min for specimens having a thickness greater than 3 mm or 75 mm/min for bars less
than 3 mm thick. The rating is also extended to products that
do not support combustion to the 100-mm reference mark.
Table 18
UL Criteria for Classifying Materials V-0, V-1, or V-2
Criteria Conditions
94V-0
94V-1
94V-2
Afterflame time for each individual
specimen, (t1 or t2)
≤ 10s
≤ 30s
≤ 30s
Total afterflame time for any
condition set (t1 + t2 for the 5
specimens)
≤ 50s
≤ 250s
≤ 250s
Afterflame plus afterglow time for
each individual specimen after the
second flame application (t2 + t3)
≤ 30s
≤ 60s
≤ 60s
Afterflame or afterglow of any
specimen up to the holding clamp
No
No
No
Cotton indicator ignited by flaming
particles or drops
No
No
Yes
Table 19 gives the ratings of selected grades of TORLON resins.
The most current ratings of TORLON resins can be found at the
Underwriters’ Laboratories web site at
http://data.ul.com/iqlink/index.asp.
Table 19
Vertical Flammability by Underwriters’ Laboratories
(UL 94)
Thickness
Grade
4203, 4203L
4301
20 MM Vertical Burn Test
Materials can be classified 94V-0, 94V-1, or 94V-2 based on
the results obtained from the combustion of samples clamped
in a vertical position.
TORLON PAI Design Guide
– 17 –
5030
in.
mm
UL 94 Rating
0.047
1.2
V-0
0.094
2.4
V-0
0.118
3.0
V-0
0.047
1.2
V-0
0.094
2.4
V-0
0.118
3.0
V-0
0.047
1.2
V-0
0.059
1.5
V-0
0.094
2.4
V-0
0.118
3.0
V-0
UL 94 Flammability Standard
FAA Flammability
TORLON 5030 and 7130 were tested by the FAA vertical
Flammability test for Transport Category Airplanes as described
in 25.853(a) and Appendix F. The results are shown in Table
20.
Samples of TORLON 5030 and 7130 were also tested for horizontal flammability (FAA Transport Category Airplanes,
25.853(b-3) and Appendix F) and 45 flammability (FAA Cargo
and Baggage Compartment, 25.855(1-a)). In both cases, the
test specimens did not ignite. Based on that result, TORLON
5030 and 7130 meet the requirements of these codes.
Table 20
FAA Vertical Flammability
Average burn length
Grade
in.
mm
TORLON 5030
0.6
15.2
TORLON 7130
0.6
15.2
UL 57 Electric Lighting Fixtures
Torlon 4203L resin was tested for conformance to the
flammability requirements of this standard. The results shown
in Table 21 show that the requirements are met.
Table 21
Electric Lighting Fixtures, Flammability Requirements,
UL 57
Grade
Test Results
TORLON 4203L
Noncombustible by Section 81.12. for thickness
of 0.040, 0.125 and 0.200 inches
(1. 0 2, 3.18, 5.08 mm)
Note: The test methods used to obtain the data in this section
measure response to heat and flame under controlled laboratory conditions detailed in the test method specified and may
not provide an accurate measure of fire hazard under actual
fire conditions. Furthermore, as Solvay Advanced Polymers has
no control over final formulation by the user of these resins
including components incorporated either internally or externally, nor over processing conditions or final physical form or
shape, these results may not be directly applicable to the
intended end use.
Flammability
– 18 –
Solvay Advanced Polymers, L.L.C.
Performance in Various
Environments
Table 22
Chemical Resistance of TORLON 4203L, 24 hr at 200°F (93°C)
(except where noted otherwise)
Chemical Resistance
TORLON polyamide-imide is virtually unaffected by aliphatic
and aromatic hydrocarbons, chlorinated and fluorinated hydrocarbons, and most acids at moderate temperatures. The polymer, however, may be attacked by saturated steam, strong
bases, and some high-temperature acid systems. The effects
of a number of specific chemicals on the tensile strength of
TORLON 4203L are presented in Table 22. Proper post-cure of
TORLON parts is necessary to achieve optimal chemical
resistance.
Chemical
Rating
Acids
Acetic acid (10%)
A
Glacial acetic acid
A
Acetic anhydride
A
Lactic acid
A
Benzene sulfonic acid
F
Chromic acid (10%)
A
Formic acid (88%)
C
Hydrochloric acid (10%)
A
Hydrochloric acid (37%)
A
Hydrofluoric acid (40%)
F
Phosphoric acid (35%)
A
Sulfuric acid (30%)
A
Bases
Ammonium hydroxide
C
(28%)
Sodium hydroxide (15%)
F
Sodium hydroxide (30%)
F
Aqueous solutions (10%)
Aluminum sulfate
A
Ammonium chloride
A
Ammonium nitrate
A
Barium chloride
A
Bromine (saturated solution, A
(120°F)
Calcium chloride
A
Calcium nitrate
A
Ferric chloride
A
Magnesium chloride
A
Potassium permanganate
A
Sodium bicarbonate
A
Silver chloride
A
Sodium carbonate
A
Sodium chloride
A
Sodium chromate
A
Sodium hypochlorite
A
Sodium sulfate
A
Sodium sulfide
A
Sodium Sulfite
A
Alcohols
2-Aminoethanol
F
n-amyl alcohol
A
n-butyl alcohol
A
Cyclohexanol
A
Ethylene glycol
A
Amines
Aniline
A
n-Butyl amine
A
Dimethylaniline
A
Chemical
Rating
Ethylene diamine
F
Morpholine
A
Pyridine
F
Aldehydes & ketones
Acetophenone
A
Benzaldehyde
A
Cyclohexanone
A
Formaldehyde (37%)
A
Furfural
C
Methyl ethyl ketone
A
Chlorinated organics
Acetyl chloride (120°F)
A
Benzyl chloride (120°F)
A
Carbon tetrachloride
A
Chlorobenzene
A
2-Chloroethanol
A
Chloroform (120°F)
A
Epichlorohydrin
A
Ethylene chloride
A
Esters
Amyl acetate
A
Butyl acetate
A
Butyl phthalate
A
Ethyl acetate
A
Ethers
Butyl ether
A
Cellosolve
A
P-Dioxane (120°F)
A
Tetrahydrofuran
A
Hydrocarbons
Cyclohexane
A
Diesel fuel
A
Gasoline (120°F)
A
Heptane
A
Mineral oil
A
Motor oil
A
Stoddard solvent
A
Toluene
A
Nitriles
Acetonitrile
A
Benzonitrile
A
Nitro compounds
Nitrobenzene
A
Nitromethane
A
Miscellaneous
Cresyldiphenyl phosphate
A
Sulfolane
A
Triphenylphosphite
A
Key to Compatibility Ratings
•
•
•
•
TORLON PAI Design Guide
– 19 –
A - Excellent – no attack, negligible effect on mechanical properties.
B - Good – slight attack, small reduction in mechanical properties.
C - Fair – moderate attack, material will have limited life.
F - Poor – material will fail, decompose, or dissolve in a short time.
Chemical Resistance
Resistance To Automotive and Aviation Fluids
Of particular interest to aerospace and automotive engineers is
the ability of a polymer to maintain its properties after exposure
to commonly used fluids. Total immersion tests show TORLON
polyamide-imide is not affected by common lubricating fluids
at 300°F (149°C), aircraft hydraulic fluid at low temperatures,
and turbine oil, even under stress at elevated temperatures. At
275°F (135°C), aircraft hydraulic fluid reduces strength slightly.
Tables 23 and 25 summarize the methods and results of specific fluid immersion tests.
Automotive Lubricating Fluids
ASTM D790 specimens were tested at room temperature after
immersion in 300°F (149°C) lubricating fluids for one month.
TORLON 4203L and 4275 have excellent property retention
under these conditions (Table 23).
Table 23
Property Retention After Immersion in Automotive
Lubricating Fluids at 300°F (149°C)
Tested at room temperature
TORLON 4203L
Flexural
strength
Weight
retained,
change
%
%
Lubricant
Motor oil 1
0.0
99.4
0.0
100.3
Transmission fluid 2
+0.2
102.7
Gear lube 3
1 Valvoline SAE 20W
2 Exxon 11933
TORLON 4275
Flexural
strength
Weight
retained,
change
%
%
0.0
95.5
0.0
94.2
+0.2
100.6
3 Penzoil 80W-90
In a separate experiment, TORLON 4301 and TORLON 4275
were exposed to 3 different versions of FORD automatic transmission fluid for 1,500 hours at 302°F (150°C). After exposure,
the tensile strength and flexural modulus was determined and
compared to the values obtained before exposure. The results
shown in Table 24 indicate excellent resistance to degradation
by these fluids.
Table 24
Aircraft Hydraulic Fluid (SKYDROL 500B)
TORLON bearing grades 4301 and 4275 were immersed in aircraft hydraulic fluid for 41 days at -108°F (-80°C) and 275°F
(135°C). The change in tensile properties is shown in Table 25.
Both TORLON grades were mildly affected by the fluid at 275°F
(135°C), showing a loss in tensile strength of about 10 percent.
It is noteworthy that this loss was not a result of embrittlement
as tensile elongation was maintained. Tests show TORLON
4203L bar specimens resist cracking, softening, and breakage
under high stress in aircraft hydraulic fluid. Low temperature
testing showed no significant effect on either grade.
Aircraft Turbine Oil, With and Without Stress
TORLON parts have exceptional resistance to Aeroshell® 500
turbine oil5 under stress at elevated temperatures. Turbine oil
affects TORLON 4203L and 7130 only slightly; after 100 hours
of exposure under stress, 4203L maintains more than 80 percent of its ultimate tensile strength at temperatures up to
400°F (204°C) without rupturing, and 7130, a graphite-fiber-reinforced grade, is even better, tolerating stress levels
of 80 percent of ultimate at temperatures up to 450°F (232°C).
Table 25
Tensile Strength After Immersion in Aircraft Hydraulic
Fluid
®
Skydrol 500B
Grade
TORLON 4301
1,000 hours at 275°F (135°C)
1,000 hours at -108°F (-80°C)
TORLON 4275
1,000 hours at 275°F (135°C)
1,000 hours at -108°F (-80°C
Tensile strength,
% retained
Elongation,
% retained
89.6
94.0
94.1
95.8
92.7
101.3
119.3
129.8
Skydrol is a registered trademark of Monsanto Company
Tested at room temperature
In another test, without stress, essentially no change in the tensile strengths of TORLON 4203L and 4301 was observed after
1000 hours in Aeroshell®* 500 at 302°F (150°C).
*Aeroshell is a registered trademark of Shell Oil Company.
Effect of FORD ATF after 1,500 hours at 302°F (150°C)
Fluid
1
2
3
Tensile Strength Retained, %
TORLON 4301 TORLON 4275
87
95
89
88
85
97
Performance in Various Environments
Flex Modulus Retained, %
TORLON 4301 TORLON 4275
97
93
93
96
94
92
– 20 –
Chemical Resistance Under Stress
TORLON parts which had been thoroughly post-cured were
tested for chemical resistance under stress. Test specimens, 5
x 0.5 x 0.125 inch (12.7 x 1.3 x 0.318 cm) were clamped over
a fixture with a 5.0 inch (12.7 cm) radius curved surface. The
test chemical was applied to the middle of each specimen for
one minute. The application was repeated after one and two
hours. Specimens were inspected after 24 hours for breakage,
cracking, swelling, and softening.
Solvay Advanced Polymers, L.L.C.
Resistance to the following chemical environments was tested:
aviation gasoline, turbine fuel (Jet A/A-1), hydraulic fluid,
methyl ethyl ketone, methylene chloride, 1,1,1 trichloroethane,
and toluene. None of the TORLON specimens showed any
breakage, cracking, swelling, or softening.
Figure 29
Water Absorption of TORLON Polymers at 73°F (23°C),
50% RH
Like other high-temperature engineering resins and composites, TORLON parts absorb water, but the rate is slow and parts
can be rapidly restored to original dimensions and properties
by drying.
Absorption Rate
TORLON polyamide-imide must be exposed to high humidity
for a long time to absorb a significant amount of water. The
rate of absorption depends on polymer grade, temperature,
humidity, and part geometry.
Weight Increase, %
Effects of Water
2.5
4203L
2.0
4301
4275
7130
5030
1.5
1.0
0.5
0.0
0
100
200
300
400
500
Time, days
Figures 29 and 30 report results obtained with uniform bars 5 x
½ x 1 8 inch (127 x 13 x 3 mm). Water absorption is dependent
on diffusion into the part and is inversely proportional to part
thickness.
Figure 30
Water Absorption of TORLON Polymers at 110°F (43°C),
90% RH
Equilibrium Absorption at Constant Humidity
5.0
4.5
Weight Increase, %
At constant humidity, a TORLON part will absorb an equilibrium
amount of water. The levels for a range of relative humidity are
shown in Figure 31 using uniform panels whose dimensions
were 5 x ½ x 1 8 inch (127 x 13 x 3 mm).
4.0
4203L
3.5
4301
4275
3.0
7130/5030
2.5
2.0
1.5
1.0
0.5
0.0
0
50
100
150
200
250
Time, days
Figure 31
Equilibrium Moisture Absorption vs. Relative Humidity
Weight Increase, %
5.0
4203L
4301
4.0
5030
7130
3.0
2.0
1.0
0.0
0
10
20
30
40
50
60
70
80
90
100
Relative Humidity, %
TORLON PAI Design Guide
– 21–
Effects of Water
Dimensional Changes
Figure 32
Small dimensional changes occur as TORLON parts absorb
water. Figures 32 and 33 show dimensional changes of the
standard test part with exposure to atmospheric moisture at
specified temperatures. As with absorption rate, the change is
greatest for TORLON 4203L resin, the grade with least filler or
reinforcement.
Dimensional Change of TORLON Polymers at 73°F (23°C),
50% RH
Original dimensions and properties can be restored by drying
TORLON parts. The temperature and time required depend on
part size and geometry. For the test panels in this study, original dimensions were restored by heating for 16 hours at 300°F
(149°C).
Dimensional Change, %
Restoration of Dimensions and Properties
0.20
0.15
0.10
0.05
0.00
Changes in Mechanical and Electrical Properties
0
Absorbed water reduces the electrical resistance of TORLON
resin and slightly changes dielectric properties. With 2 percent
moisture, TORLON specimens had volume and surface
resistivities of 1 x 1016 ohm/inch (3 x 1014 ohm/m) and 1 x 1017
ohm respectively, and dielectric strength of 620 V/mil (24
kV/mm).
200
300
400
500
Time, days
Figure 33
Dimensional Change of TORLON Polymers at 110°F
(43°C), 90% RH
0.50
Dimensional Change, %
To illustrate the change in mechanical properties with water
absorption, test specimens were immersed in water until their
weight increased by 2 percent. Table 26 compares the properties of these panels with those of panels conditioned for 40
hours at 73°F (23°C) and 50 percent relative humidity. A slight
reduction in stiffness is the most noticeable change.
100
0.40
0.30
0.20
0.10
0.00
0
50
100
150
200
Time, days
Table 26
Property Change of TORLON 4203L at 2% absorbed
water
Property
Tensile strength
-7
Tensile modulus
-11
Elongation
Shear strength
Performance in Various Environments
– 22–
Change, %
13
1
lzod impact strength
20
Dielectric constant
18
Dissipation factor
53
Solvay Advanced Polymers, L.L.C.
Absorbed water limits the rate at which TORLON parts can be
heated. Sudden exposure to high temperature can distort or
blister parts unless absorbed water is allowed to diffuse from
the part. Solvay Advanced Polymers uses the term “thermal
shock temperature” to designate the temperature at which any
distortion occurs upon sudden exposure to heat.
Thermal Shock Temperature vs. Moisture Content of
TORLON 4203L
Figure 34 relates thermal shock temperature to moisture content for TORLON 4203L, the grade most sensitive to water
absorption. At 2½ percent absorbed water (which is equilibrium at 50 percent relative humidity and room temperature) the
thermal shock temperature is well over 400°F (204°C). Thermal shock is related to exposure time in Figure 35. Even after
over 200 hours at 57.8 percent relative humidity and 73°F
(23°C), the test part made with TORLON 4203L did not distort
until sudden exposure to over 400°F (204°C). Other grades of
TORLON resin exhibit lower equilibrium water absorption (refer
to Figure 31) and their thermal shock temperatures are therefore higher. Thermal shock temperature can be restored to its
highest level by drying at 300°F (149°C) for 24 hours for each
1 inch (3 mm) of part thickness.
8
TORLON PAI Design Guide
– 23 –
300
500
250
200
400
150
300
100
200
50
100
0
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Moisture Content, weight %
Figure 35
Thermal Shock Temperature vs. Exposure Time for
TORLON 4203L
600
300
500
250
200
400
150
300
100
200
50
100
0
0
0
50
100
150
200
Thermal Shock Temperature, C
The bars are then placed in a circulating air oven preheated to
the test temperature. After one hour, the samples are removed,
visually inspected, and measured. Failure occurs if blisters or
bubbles appear or if dimensions increase by more than 0.001
inch (0.025 mm). The lowest temperature at which failure is
seen is designated the thermal shock temperature.
Thermal Shock Temperature, F
To determine the thermal shock temperature, test specimens 5
x ½ x 1 8 inch (127 x 13 x 3 mm) are exposed to 57.8 percent
relative humidity and 73°F (23°C) over a specified period of
time. The TORLON resin will absorb water. The amount
absorbed will depend upon the exposure time and the grade of
TORLON resin. The dimensions of the bars are measured and
recorded.
600
Thermal Shock Temperature, C
Figure 34
Thermal Shock Temperature, F
Constraints on Sudden High Temperature Exposure
250
Exposure Time, days at 57.8% RH
Effects of Water
®
Weather-Ometer Testing
Figure 36
Tensile bars conforming to ASTM test method D 1708 were
exposed in an Atlas Sunshine Carbon Arc Weather-Ometer.
Bars were removed after various exposure periods and tensile
strength and elongation were determined. The test conditions
were a black panel temperature of 145°F (63°C), 50 percent
relative humidity and an 18-minute water spray every 102
minutes.
The Elongation of TORLON 4203L is Essentially Constant
after Exposure to Simulated Weathering
14.0
4203L
12.0
Elongation, %
TORLON molding polymers are exceptionally resistant to degradation by ultraviolet light. TORLON 4203L resin did not degrade
after 6,000 hours of Weather-Ometer exposure (Figures 36 and
37) which is roughly equivalent to five years of outdoor exposure. The bearing grades, such as 4301, contain graphite powder which renders the material black and screens UV radiation.
These grades are even more resistant to degradation from outdoor exposure.
10.0
8.0
6.0
4.0
2.0
0.0
10
100
1000
10000
Exposure Time, hours
Resistance to Gamma Radiation
Figure 37
Change in Tensile Strength of TORLON 4203L With
Exposure to Simulated Weathering
30
200
Tensile Strength, kpsi
4203L
25
150
20
15
100
10
50
5
0
10
100
Tensile Strength, MPa
Figure 38 shows the negligible effect gamma radiation has on
TORLON polyamide-imide — only about 5 percent loss in tensile strength after exposure to 109 rads.
0
10000
1000
Exposure Time, hours
Figure 38
Properties Change of TORLON 4203L Due to Gamma
Radiation
50
Elongation
Tensile Strength
Flexural Modulus
Change in Property, %
40
30
20
10
0
-10
-20
-30
-40
-50
100
101
102
103
104
105
106
107
108
109
Radiation Exposure Level, rads
Performance in Various Environments
– 24–
Solvay Advanced Polymers, L.L.C.
Electrical Properties
Most TORLON grades provide electrical insulation. TORLON
polyamide-imide provides a unique combination of high temperature service and ease of moldability into complex electrical
and electronic parts. Special grades of TORLON engineering
polymer are conductive. TORLON 7130, a conductive grade,
effectively shields electromagnetic interference. The design
engineer should consider the significant electrical properties of
a material, such as those summarized in Table 27.
Table 27
TORLON Polymers for Insulating
Important Electrical Considerations
TORLON PAI resin has excellent electrical insulating properties
and maintains them in a variety of environments. TORLON
grades 4203L and 5030 have high dielectric strengths and
high volume and surface resistivity as shown in Table 28.
Property
ASTM
test
method
Dielectric constant
D150
The ratio of the capacity of a
condenser filled with the material to
the capacity of an evacuated
capacitor. It is a measure of the
ability of the molecules to become
polarized in an electric field. A low
dielectric constant indicates low
polarizability; thus the material can
function as an insulator.
Dissipation factor
DI50
A measure of the dielectric loss
(energy dissipated) of alternating
current to heat. A low dissipation
factor indicates low dielectric loss,
while a high dissipation factor
indicates high loss of power to the
material, which may become hot in
use at high frequencies.
Volume resistivity
Surface resistivity
Dielectric strength
D257
D257
D149
Significance
The TORLON polyamide-imide grades intended for wear-resistant applications – 4301, 4275, and 4435 – contain graphite
which under some conditions can conduct electricity. Although
these materials have high resistivities by the ASTM test method
D 257, which uses direct current for its measurements, these
materials may demonstrate some conductivity at higher frequencies and voltages.
Table 28
Electrical Properties of TORLON Resins
The electrical resistance of a unit
cube calculated by multiplying the
resistance in ohms between the
faces of the cube by the area of the
faces. The higher the volume
resistivity, the better the material will
function as an insulator.
The resistance to electric current
along the surface of a one square
centimeter sample of material. Higher
surface resistivity indicates better
insulating properties.
A measure of the voltage an
insulating material can take before
failure (dielectric breakdown). A high
dielectric strength indicates the
material is a good insulator.
Volume resistivity
(ASTM D257)
ohm•cm
Surface resistivity
(ASTM D257)
ohm
Dielectric strength,
0.040 in
(ASTM D 149)
V/mil
kV/mm
Dielectric constant
(ASTM D150)
103 Hz
106 Hz
Dissipation factor
(ASTM D150)
103 Hz
106 Hz
TORLON Grade
4275*
4435*
4203L
4301*
2 x 1017
8 x 1015
8 x 1015
2 x 107
2 x 1017
5 x 1018
8 x 1017
4 x 1017 6 x 1010
1 X 1018
580
24
5030
840
33
4.2
3.9
6.0
5.4
7.3
6.6
4.4
4.2
0.026
0.031
0.037
0.042
0.059
0.063
0.022
0.023
*Contains graphite powder. By these tests, they behave as insulators, but they may
behave in a more conductive manner at high voltage or high frequency.
TORLON PAI Design Guide
– 25 –
TORLON Polymers for Insulating
minute. Or in the SI system, the 12.7 mm shaft rotating at 1200
rpm, would have a velocity of 47.9 meters per minute or (dividing by 60) 0.8 meters per second.
Service in Wear-Resistant
Applications
An Introduction to TORLON PAI Wear-Resistant Grades
New possibilities in the design of moving parts are made available by TORLON wear-resistant grades: 4301, 4275, and 4435.
These materials offer high compressive strength and modulus,
excellent creep resistance, and outstanding retention of
strength and modulus at elevated temperatures, as well as
self-lubricity and low coefficients of thermal expansion, which
make them prime candidates for wear surfaces in severe service. TORLON PAI bearings are dependable in lubricated,
unlubricated, and marginally lubricated service. Some typical
applications which lend themselves to this unique set of properties are plain bearings, thrust washers, seal rings, vanes,
valve seats, bushings, and wear pads.
To calculate the pressure, divide the total load by the area. For
sleeve bearings, the projected area is typically used, so the
length of the sleeve would be multiplied by the inside diameter
of the bearing as shown in Figure 39. In US customary units,
the pressure is expressed in pounds per square inch. In the SI
system, pressure is usually expressed in Pascals, which is the
same as Newtons per square meter.
Figure 39
Calculating Bearing Projected Area
Bearing Design Concepts
Whenever two solids rub against each other, some wear is
inevitable. The force pressing the sliding surfaces together
(pressure) and the speed at which the sliding occurs (velocity)
impact the rate at which wear occurs.
Projected Area
Length
Inside
Diameter
Wear Rate Relationship
The rate at which wear occurs can be related to the pressure
and velocity by the following empirical equation:
Thrust Washers
To calculate the sliding velocity of a thrust washer application,
the mean diameter is typically used to determine the length per
revolution. For example, a thrust washer with an outside diameter of 3 inches (76 mm) and an inside diameter of 2 inches
(51 mm), would have a mean diameter of 2.5 inches (63.5
mm), and the distance slid per revolution would be obtained by
multiplying that diameter by π or 3.14. That value would be
multiplied by the rpm and, in the US system, divided by 12 to
t = KPVT
where:
t = wear
K = wear factor determined at a given P and V
P = pressure on bearing surface
V = bearing surface velocity
T = time
This equation seems to suggest that the wear will be directly
proportional to the pressure and velocity. That would be true if
the wear factor K were constant. For polymeric materials, the
wear factor is not constant and varies with the pressure and
velocity. The equation is only useful for calculating the wear
depth at a particular PV from the wear rate at that PV and the
expected service life, corrected for duty factor.
Figure 40
Thrust Washer Calculation Example
3.00”
(76.2 mm)
US Customary Units
Area = π x (3/2) - π x (2/2)
Area = 3.14 x (2.25 - 1.0)
Area = 3.14 x (1.25)
Area = 3.925 in2
2
Calculating the Pressure and Velocity
Bearings
A typical plain bearing application consists of a sleeve bearing
around a rotating shaft. To calculate the sliding velocity in feet
per minute, multiply the shaft diameter in inches by the revolutions per minute (rpm), and then by 0.262; or to get the velocity
in meters per minute, multiply the shaft diameter in millimeters
by the rpm, then by 0.003144. For example, a ½-inch shaft
rotating at 1200 rpm would have a velocity of 157.2 feet per
Service in Wear-Resistant Applications
– 26–
2
SI Units
Area = π x (76.2/2) - π x (50.8/2)
Area = 3.14 x (1451 - 645)
Area = 3.14 x 806
Area = 2531 mm2
2
Area = 0.002531 m
2
2.00”
(50.8 mm)
2
Solvay Advanced Polymers, L.L.C.
get velocity in feet per minute. In the SI system, the mean
diameter in millimeters would be multiplied by 3.14 and the
rpm, and then divided by 60000 to get velocity in meters per
second. To continue the example, assume an rpm of 100, then
the velocity in U.S. units is 2.5 x 3.14 x 100 ÷12, or 65.4 feet
per minute. In SI units, the velocity would be 63.5 x 3.14 x 100
÷ 60000, or 0.33 meters per second.
The method used for the wear resistance data in this document
was ASTM D 3702, using a manual thrust bearing, 3-pin
machine. The test specimens were prepared by injection molding a disc and machining it to the final configuration shown in
Figure 42.
To calculate the pressure, the total load is divided by the bearing area. Figure 40 depicts the thrust washer used for this
example and details the calculation of the bearing area. If the
load on the washer is 100 pounds (444.8 Newtons), the pressure would be 100 divided by 3.925 or 25.47 psi. In the SI system, the pressure would be obtained by dividing the 444.8 N by
0.002531 m2. The result (175740.8) would have units of N/m2,
which is defined as the Pascal (Pa). Dividing this value by 106
gives a value of 0.1757 MPa.
Thrust Washer Test Specimen
Figure 42
For this example, the PV would be 1666 ft-lb/in2min or 0.058
MPa-m/s.
PV Limit Concept
Either increasing the pressure or the velocity will cause added
friction and subsequently additional frictional heat. Because the
properties of polymeric materials vary with temperature, the
product of the pressure and velocity is useful for predicting the
performance of a polymeric bearing material. If a polymeric
bearing material is tested at varying pressures and velocities,
and the results related to the pressure-velocity product (PV),
the behavior shown in Figure 41 is typical. At low to moderate
PV’s, wear is low. As the PV is increased, at some point the
wear becomes rapid. The PV at which this transition occurs is
commonly called the PV limit or limiting PV. Due to heat of friction, bearings in service above the PV limit of the material wear
very rapidly and may actually melt.
The samples were tested against a stationary washer made of
AISI C-1018 steel having a surface finish of 16 µin. Testing was
performed at ambient temperature and humidity without any
external lubrication. Thrust washer specimens were broken in
to remove any surface irregularities at a velocity of 200 ft/min
and a pressure of 125 psi for a period of 20 hours. Then each
sample was tested at the specified velocity and pressure for 20
hours. Height measurements were taken before and after at 4
equidistant points on the thrust washer disk and the average
wear depth in inches was reported and used in the calculation
of the wear factor.
TORLON Wear-Resistant Grades
Figure 41
Material wear rate is a function of the Pressure-Velocity
(PV) product
Three grades of TORLON PAI have been compounded with
additives to improve their resistance to wear in unlubricated
service. These grades are 4301, 4275, and 4435.
Wear factor, K
Low wear factors (K) are characteristic of wear resistant materials. Fluoropolymers, which have low coefficients of friction,
have very low wear factors, but limited mechanical properties
and poor creep resistance. At low PV’s, TORLON wear resistant
grades have wear factors comparable to filled polytetrafluoroethylene (pTFE), a fluoropolymer, but TORLON polymers offer
superior creep resistance and strength.
TORLON polymers have wear factors similar to those of more
expensive polyimide resins, and there is a distinct cost advantage in choosing TORLON polyamide-imide. In addition,
TORLON resins are injection moldable; polyimides are not.
PV
Limit
PV
Measuring Wear Resistance
There are a variety of methods for evaluating relative wear
resistance. Because of the large number of independent variables, there is little correlation between methods.
TORLON PAI Design Guide
– 27 –
TORLON Wear-Resistant Grades
The wear factors obtained when the three wear resistant
grades of TORLON PAI were tested at various PV’s are shown in
Table 31.
Table 31
Wear Factors and Wear Rates
U.S. Units
Velocity - 50 ft/min
Pressure, psi
PV
200
10000
500
25000
1000
50000
1500
75000
2000
100000
Velocity - 200 ft/min
50
10000
125
25000
250
50000
375
75000
500
100000
Velocity - 800 ft/min
12.5
10000
31.25
25000
62.5
50000
93.75
75000
125
100000
4301
17
42
82
NT
NT
Wear Factor, 10-10 in3-min/ft-lb-hr
TORLON
Vespel®
PEEK™
4275
4435
SP-21 X50FC30
8
NT
19
45
49
NT
52
129
55
27
38
249
28
20
28
melted
24
20
cracked
NT
4301
17
105
410
NT
NT
Wear Rate, 10-6 in/hr
TORLON
Vespel®
4275
4435
SP-21
8
NT
19
122.5
NT
130
275
135
190
210
150
210
240
200
cracked
17
83
156
NT
NT
18
39
74
222
melted
NT
98
33
21
20
18
104
47
36
28
74
69
168
168
melted
17
208
780
NT
NT
18
98
370
1665
melted
95
385
896
NT
NT
13
69
118
214
melted
NT
52
69
63
52
40
21
154
1419
melted
NT
95
962
4480
NT
NT
13
172
590
1605
melted
92
77
52
PEEK™
X50FC30
45
322
1245
melted
NT
NT
245
165
158
200
18
260
235
270
280
74
172
840
1260
melted
460
578
520
52
172
315
390
400
21
385
7095
melted
NT
SI Units
Wear Factor, 10-10 mm-s/mPa-hr
Wear Rate, 10-6 m/hr
Velocity - 0.25 m/s
Pressure, MPa
1.379
3.447
6.895
10.342
13.790
Velocity - 1.02 m/s
0.345
0.862
1.724
2.586
3.447
Velocity - 4.06 m/s
0.086
0.215
0.431
0.646
0.862
PV
0.350
0.876
1.751
2.627
3.503
4301
8
30
59
NT
NT
TORLON
4275
6
36
40
20
17
4435
NT
NT
20
15
15
Vespel®
SP-21
14
38
28
20
cracked
PEEK™
X50FC30
33
94
181
melted
NT
4301
0.3
2.7
10.4
NT
NT
TORLON
4275
0.2
3.1
7.0
5.3
6.1
4435
NT
NT
3.4
3.8
5.1
Vespel®
SP-21
0.5
3.3
4.8
5.3
cracked
PEEK™
X50FC30
1.1
8.2
31.6
melted
NT
0.350
0.876
1.751
2.627
3.503
12
60
113
NT
NT
13
28
54
126
melted
NT
71
24
15
15
13
75
34
26
20
54
50
122
122
melted
0.4
5.3
19.8
NT
NT
0.5
2.5
9.4
33.1
melted
NT
6.2
4.2
4.0
5.1
0.5
6.6
6.0
6.9
7.1
1.9
4.4
21.3
32.0
melted
0.350
0.876
1.751
2.627
3.503
69
102
135
NT
NT
9
50
86
155
melted
NT
NT
67
56
38
38
50
46
38
29
15
112
1030
melted
NT
2.4
8.9
23.6
NT
NT
0.3
4.4
15.0
40.8
melted
NT
NT
11.7
14.7
13.2
1.3
4.4
8.0
9.9
10.2
0.5
9.8
180.2
melted
NT
Service in Wear-Resistant Applications
– 28 –
Solvay Advanced Polymers, L.L.C.
These data which are plotted in Figures 43 through 45 clearly
show that TORLON 4435 has superior wear resistance over a
wide PV range.
Figure 43
Wear Resistance at Low Velocity
Pressure, MPa
2
4
6
8
10
Wear Depth, µin/hr
1000
30
25
800
20
600
15
400
10
200
5
0
0.0
0.5
1.0
Table 32
35
TORLON 4301
TORLON 4275
TORLON 4435
Vespel SP-21
Victrex X50FC30
1200
The wear data presented in Table 31 and Figures 43 through
45 were determined using C1018 steel hardened to 24 on the
Rockwell C scale. Other metals were tested against TORLON
4301 to evaluate the effect of the mating surface on wear
resistance. The results are shown in Table 32.
12
Velocity 50 ft/min (0.25 m/s)
Wear Characteristics of TORLON 4301 PAI Against
Various Metals
Wear Depth, µm/hr
1400
0
Effect of Mating Surface on Wear Rate
Metal used as mating surface for TORLON 4301
Aluminum die
316
casting alloys
Stainless
Brass
C1018
C1018
steel
A360
A380
(Standard)
Soft
Rockwell hardness, C scale
24
6
17
-15
-24
-28
Relative Wear Factor at High Velocity
1.0
1.4
7.5
2.1
1.3
1.2
Relative Wear Factor at Low Velocity
1.0
1.2
1.2
1.5
1.5
0.9
0
2.0
1.5
Pressure, kpsi
Figure 44
Wear Resistance at Moderate Velocity
Lubricated Wear Resistance
Pressure, MPa
1400
0
1
2
The impressive performance of TORLON bearing grades in
nonlubricated environments is insurance against catastrophic
part failure or seizure upon lube loss in a normally lubricated
environment. In a transmission lubricated with hydrocarbon
fluid, TORLON thrust washers are performing well at PVs of
1,300,000 ft-lbs/in2-min. In a water-lubricated hydraulic motor
vane, excellent performance has been attained at over
2,000,000 PV. Table 33 summarizes the wear characteristics of
TORLON 4301 immersed in hydraulic fluid.
3
Velocity 200 ft/min (1.02 m/s)
Wear Depth, µin/hr
TORLON 4301
TORLON 4275
TORLON 4435
VESPEL SP-21
Victrex X50FC30
1000
800
30
20
600
400
10
Wear Depth, µm/hr
40
1200
200
0
0
100
200
300
0
500
400
Table 33
Pressure, psi
Lubricated wear resistance of TORLON 4301
Figure 45
Wear Resistance at High Velocity
Pressure, MPa
0.2
0.4
0.6
0.8
200
Velocity 800 ft/min (4.06 m/s)
TORLON 4301
TORLON 4275
TORLON 4435
Vespel SP-21
Victrex X50FC30
7000
Wear Depth, µin/hr
1.0
6000
150
5000
4000
100
3000
2000
50
45,000
Wear factor, K
(10-10 in3•min/ft•lb•hr)
1.0
Coefficient of friction, static
0.08
Coefficient of friction, kinetic
0.10
Wear depth at 1,000 hours, in (mm)
0.0045 (0.11 mm)
Wear Depth, µm/hr
0.0
8000
PV (P/V = 50/900)
1000
0
0
0
20
40
60
80
100
120
140
Pressure, psi
TORLON PAI Design Guide
– 29 –
Lubricated Wear Resistance
Figure 46
The length of post-cure will depend on part configuration,
thickness, and to some extent on molding conditions. Very long
exposure to 500°F (260°C) is not detrimental to TORLON parts.
The suitability of shorter cycles must be verified experimentally.
Extended Cure at 500°F (260°C) Improves Wear
Resistance
600
500
500
400
300
400
200
300
100
0
0
2
4
6
8
10
12
Cure Temperature, F
The wear resistance of TORLON parts depends on proper
post-cure. A thorough and complete post-cure is necessary to
achieve maximum wear resistance. To illustrate the dependence of wear resistance on post-cure, a sample of TORLON
4301 was post-cured through a specified cycle* and tested for
wear resistance at various points in time. The results of that
test and the cure cycle are shown in Figure 46. In this case, the
Wear Factor, K, reached a minimum after eleven days, indicating achievement of maximum wear resistance.
Wear Factor, k x 10-10
Wear Resistance and Post-Cure
200
14
Cure Cycle, days
Cure cycles are a function of part geometry.
Service in Wear-Resistant Applications
– 30 –
Solvay Advanced Polymers, L.L.C.
Bearing Design
Figure 47
When designing a bearing to be made of TORLON PAI, it is
important to remember that adequate shaft clearance is critical. With metal bearings, high clearances tend to result in shaft
vibration and scoring. PAI bearings are much more resilient,
dampen vibrations, and resist scoring or galling. The bearing
inside diameter will be determined by adding the total running
clearance to the shaft outside diameter. The total running clearance is the total of the basic clearance, the adjustment for high
ambient temperature, and an adjustment for press fit interference if the bearing is press fit.
Basic Bearing Shaft Clearance
To give an example of how to properly size a PAI bearing, consider this hypothetical situation with a shaft diameter of 2
inches (51 mm) and bearing wall thickness of 0.2 inches (5
mm) to operate at an ambient temperature of 150°F (65°C).
The PAI bearing is to be press fit into a steel housing. The basic
clearance from Figure 47 is 9 mils or 0.009 inches (0.23 mm).
The additional clearance for the elevated ambient temperature
is obtained by multiplying the factor from Figure 48 (0.0085) by
the wall thickness to obtain 0.0017 inches (0.04 mm). The recommended interference for the press fit is 0.005 inches (0.13
mm). Because the inside diameter of the bearing will be
decreased by the amount of the interference, that amount is
added to the clearance. Therefore the total clearance will be
the basic clearance 0.009 in. + the temperature clearance
0.0017 + the interference 0.005 to give 0.0157 in. (0.40 mm).
Therefore the inside diameter of the PAI bearing should be
2.0157 inches (51.2 mm).
25
50
75
100 125 150 175 200 225 250
0.7
25
0.6
20
0.5
0.4
15
0.3
10
0.2
5
0.1
0
0
1
2
3
4
5
6
7
8
9
Basic Shaft Clearance, mm
Basic Shaft Clearance, mils
30
0.0
10
Shaft Diameter, inches
Figure 48
Clearance Factor for Elevated Ambient Temperature
Ambient Temperature, C
Temperature/Wall Thickness Factor
Figure 47 shows the basic clearance as a function of shaft
diameter. If the bearing is to be used at ambient temperatures
greater than room temperature, then the factor shown in Figure
48 should be applied. Figure 49 gives the recommended allowance for using a press fit bearing.
Shaft Diameter, mm
0
0.016
0
50
100
150
200
250
0.014
0.012
0.010
0.008
0.006
0.004
0.002
0.000
100
200
300
400
500
Ambient Temperature, F
Figure 49
Press Fit Interference
Housing Inside Diameter, mm
25
50
75
100 125 150 175 200 225 250
0.30
10
0.25
8
0.20
6
0.15
4
0.10
2
0.05
0
0
1
2
3
4
5
6
7
8
9
Press Fit Interference, mm
Press Fit Interference, mils
12
0
0.00
10
Housing Inside Diameter, inches
TORLON PAI Design Guide
– 31 –
Bearing Design
Industry and Agency Approvals
TORLON engineering polymers have been tested successfully
against many industry standards and specifications. The following list is a summary of approvals to date, but should not be
considered inclusive, as work continues to qualify TORLON
polyamide-imide for a myriad of applications.
ASTM D 5204 Standard Classification System for
Polyamide-imide (PAI) Molding and Extrusion Materials
National Aeronautics and Space Administration
NHB8060.1 “Flammability, Odor, and Offgassing
Requirements and Test Procedures for Materials in
Environments that Support Combustion” TORLON 4203L
and 4301 have passed the NASA spacecraft materials
requirements for non-vacuum exposures per NHB8060.1.
Society of Automotive Engineers-Aerospace Material
Specifications
TORLON Grade
ASTM D 5204 Designation
4203L
or
or
PAI000R03A56316E11FB41
PAI011M03
PAI021M03
4301
or
or
PAI000L15A32232E12FB42
PAI012L15
PAI022L15
4275
or
or
PAI000L23A22133E13FB42
PAI012L23
PAI022L23
4435
or
PAI0120
PAI0220
5030
or
or
PAI000G30A61643E15FB46
PAI013G30
PAI023G30
Vertical Flammability
All TORLON grades have been awarded a 94 V-0
classification. See Table 19 on page 17.
7130
or
or
PAI000C30A51661FB47
PAI013C30
PAI023C30
Continuous Use
The Relative Thermal Indices of TORLON 4203L, 4301, and
5030 are shown in Table 9 on page 12.
AMS 3670 is the specification for TORLON materials. The
specification suggests applications requiring a low
coefficient of friction, thermal stability, and toughness up to
482°F (250°C). TORLON 4203L, 4275, 4301, 5030, and
7130 are covered in the detail specifications:
AMS 3670/1-TORLON 4203L
AMS 3670/2-TORLON 4275
AMS 3670/3-TORLON 4301
AMS 3670/4-TORLON 5030
AMS 3670/5-TORLON 7130
Underwriters’ Laboratories
Federal Aviation Administration
TORLON 5030 and 7130 pass FAA requirements for
flammability, smoke density, and toxic gas emissions.
Military Specification MIL-P-46179A
This specification was cancelled on July 27, 1994 and ASTM
D 5204 was adopted by the Department of Defense. The following cross reference table appears in the adoption notice.
TORLON
Grade
Type
4203L
I
4301
II
1
PAIOOOL15A32232E12FB42
4275
II
2
PAIOOOL23A22133E13FB42
5030
III
1
PAIOOOG30A61643E15FB46
7130
IV
Class
ASTM D 5204
PAIOOOR03A56316EllFB41
Service in Wear-Resistant Applications
PAIOOOC30A51661FB47
– 32 –
Solvay Advanced Polymers, L.L.C.
Structural Design
Material Efficiency—Specific
Strength and Modulus
Reducing weight can be the key to lower cost, reduced friction,
and decreased energy consumption. When a TORLON engineering polymer replaces metal, the TORLON part can support
an equivalent load at significantly lower weight.
The ratio of a material’s tensile strength to its density (specific
strength) provides information about “material efficiency” The
specific strength of TORLON 5030, for example, is 5.45 x 105
in-lbs/lb (1.27 x 105 J/kg) compared with 3.1 x 105 in-lbs/lb
(7.75 x 105 J/kg) for stainless steel. Therefore, a TORLON 5030
part will weigh almost 40% less than a stainless steel part of
equivalent strength. Similarly, the specific modulus of a material is of interest when stiffness of the part is crucial to
performance.
Comparison of material efficiency data in Table 34 and Figure
shows that TORLON PAI can beat the weight of many metal
parts.
Table 34
Specific Strength and Modulus of TORLON polymers
and Selected Metals
Specific strength
105
in-lbf/lb
107
J/kg
Specific stiffness
107
in-lbf/lb 106 J/kg
TORLON 4203L
5.45
1.36
1.37
3.42
TORLON 5030
5.12
1.28
2.43
6.06
TORLON 7130
5.44
1.36
5.96
14.85
Figure 50
Specific Strength of TORLON Resins vs. Metal
Aluminum Alloys, Heat Treated
1.74
10.50
26.15
Magnesium AE42-F
5.23
1.30
10.05
25.02
Carbon Steel, C1018
2.25
0.56
10.05
25.02
Stainless Steel, 301
3.10
0.77
9.66
24.05
Titanium 6-2-4-2
8.10
2.02
10.43
25.98
TORLON PAI Design Guide
– 33 –
2.0
TORLON
Mg
6
1.5
Steel
4
1.0
2
0.5
0
0.0
Material
Specific Strength, 105 J/kg
7.00
Aluminum
6242
2024
Ti
8
SS301
24.91
C1018
10.00
AE42F
1.34
2024
5.39
2011
2011
10
DC296
24.66
7130
9.90
5030
0.98
4203L
3.95
Specific Strength, 105 in-lbf/lb
Die Casting, 296
Geometry and Load Considerations
Example 1–Short-term loading
The maximum bending stress, Smax, occurs at
In the early stages of part design, standard stress and deflection formulas should be applied to ensure that maximum working stresses do not exceed recommended limits.
L/2 and M =
Examples of Stress and Deflection Formula
Application
S max =
Recommended maximum working stresses for TORLON engineering polymers appear in Table 35 on page 36. To illustrate
how these values may be used, the maximum load for a beam
made of TORLON 5030 will be calculated under various loading
conditions at room temperature. Figure 51 shows the beam
dimensions and the calculation of the moment of inertia (I).
WL
.
4
WLc
4I
Solving for W and substituting the recommended maximum
working stress for TORLON 5030 under a short-term load at
room temperature:
Wmax =
4S max I (4)(17800 psi)(0.0026 in 4 )
= 247 lb
=
Lc
(3.0 in.)(0.25 in.)
Figure 51
Beam used in examples
Therefore, the maximum short-term load for a TORLON 5030
beam at room temperature is approximately 247 pounds.
W
The maximum deflection for this beam is:
d = 0.50
L = 3.0
b = 0.25
Ymax =
WL3
at
48EI
L
2
Where E is the flexural modulus of TORLON 5030 obtained
from Table 3.
Ymax =
W = Load, lb
L = Length of beam between supports, in
c = Distance from the outermost point in tension to
the neutral axis, in
(247 lb)(3.0 in) 3
= 0.034 in.
(48)(15.6 × 10 5 psi)(0.0026 in 4 )
Therefore, the predicted maximum deflection is 0.034 in.
b = Beam width, in
d = Beam height, in
I = Moment of inertia, in4
Example 2-Steady load
In this example:
In this example, the load is long-term. Creep is considered to
be the limiting factor. The maximum load which may be applied
to the TORLON 5030 beam is:
L = 3.0 in
c = 0.25 in
b = 0.25 in
d = 0.50 in
Wmax =
I=
bd3 (0.25 in.) (0.50 in.) 3
=
= 0.0026 in 4
12
12
4S max I (4)(17000)(0.0026)
=
= 236 lb.
Lc
(3.0)(0.25)
To calculate the maximum deflection of the beam under a
steady load, the apparent (creep) modulus (Ea) is used rather
than the flexural modulus. Because material properties are
time dependent, a finite period is selected. In this example,
maximum deflection after 100 hours is calculated.
M = Load x distance to support, in•lb
The apparent modulus at 100 hours can be estimated by dividing the steady load recommended maximum working stress
from Table 35 by the assumed maximum strain (1.5 percent).
Geometry and Load Considerations
– 34 –
Solvay Advanced Polymers, L.L.C.
Figure 52
Ea =
Stress Concentration Factor for Circular Stress Raiser
(elastic stress, axial tension)
17000 psi
= 1.13 × 10 6 psi
0.015
Ymax =
3
Stress Concentration Factor, k
Substituting:
3
WL
(236)(3.0)
=
= 0.045 in.
48E aI (48)(1.13 × 10 6 )(0.0026)
Maximum deflection at L/2 is predicted to be 0.045 inch.
Example 3-Cyclic load
When materials are stressed cyclically, failures will occur at
stress levels lower than the material’s ultimate strength due to
fatigue. To calculate the maximum cyclic load our beam can
handle for a minimum of 10,000,000 cycles:
Wmax =
3.0
2.5
2.0
1.5
1.0
4203L
5030
7130
Metal
0.5
0.0
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
d/D
P
D
d
P
4S max I (4)(4550)(0.0026)
=
= 63 lb
Lc
(3.0)(0.25)
Stress Concentration
Part discontinuities, such as sharp corners and radii, introduce
stress concentrations that may result in failure below the recommended maximum working stress. It is, therefore, critical
that a part be designed so that the stress field is as evenly distributed as possible.
Circular perforations give rise to stress concentrations, but as
Figure 52 demonstrates, TORLON polyamide-imide is less sensitive than metal.
TORLON PAI Design Guide
– 35 –
Stress Concentration
Maximum Working Stresses for TORLON Resins
End use conditions restrict the allowable working stresses for a
structural member. Prototype evaluation is the best method of
determining the suitability of TORLON parts. The data summarized in Table 35 are useful early in the design process for use
in the engineering equations for the proposed part.
Table 35
Maximum Working Stresses for Injection Molded TORLON Resins
TORLON grade
English units (psi)
Temperature, °F
4203L
4301
4275
4435
5030
7130
73
17,000
14,000
13,000
9,600
17,800
17,600
275
10,000
9,800
9,800
7,800
13,900
13,700
450
5,700
6,400
4,900
4,500
9,800
9,400
Steady load (creep),
73
7,000
10,000
9,500
17,000
17,000
<1.5% strain, 100 hrs.
200
6,500
7,500
7,900
15,000
15,000
Short term load
400
5,000
6,000
6,000
10,000
10,000
Cyclic load,
73
3,850
3,000
2,800
2,000
4,550
5,250
107
275
2,450
2,100
2,100
1,620
3,500
4,200
450
1,400
1,350
1,050
950
2,450
2,800
cycles
Sl units (MPa)
Short term load
Steady load (creep),
<1.5% strain, 100 hrs.
Temperature, °C
23
117
96
89
66
122
121
135
69
67
67
54
96
94
232
39
44
34
31
67
55
23
48
69
65
117
117
93
45
52
54
103
103
204
34
41
41
69
69
Cyclic load,
23
26
21
19
14
31
36
107
135
17
14
14
11
24
29
232
10
9
7
6
17
19
cycles
Geometry and Load Considerations
– 36 –
Solvay Advanced Polymers, L.L.C.
®
Designing with TORLON Resin
Fabrication Options
TORLON polyamide-imide can be molded using any of three
conventional molding techniques; injection, compression and
extrusion. Each has advantages and limitations.
Injection Molding
TORLON parts can be injection molded to fine detail. Of the
three methods, injection molding produces parts of the highest
strength. When a large quantity of complex parts is required,
injection molding can be the most economical technique due to
short cycle times and excellent replication. Part thickness is
limited by the flow length versus thickness relationship of the
polymer. Thickness is limited to a maximum of 5 8 inch (15.9
mm).
Extrusion
TORLON polymers can be extruded into profiles and shapes
such as rods, tubing, sheet, film and plates. Small parts with
simple geometries can be economically produced by combining extrusion molding and automatic screw machining.
TORLON rod and plate stock are available in a variety of sizes.
Contact your Solvay Advanced Polymers representative for
information on approved sources.
Compression Molding
Large parts over 5/8 inch (15.9 mm) thick must be compression-molded. Tooling costs are considerably lower compared
with other molding techniques. Compression-molded parts will
generally be lower in strength than comparable injection-molded or extruded parts, but have lower stresses and are
therefore easier to machine. Compression molded rod, OD/ID
tube combinations and compression molded plates are available in a variety of sizes and thickness. Contact your Solvay
Advanced Polymers representative for information on approved
sources.
TORLON PAI Design Guide
– 37 –
Compression Molding
Figure 53
Post-Curing TORLON Parts
Gradual Blending Between Different Wall Thicknesses
TORLON parts must be post-cured. Optimal properties, especially chemical and wear resistance, are only achieved with
thorough post-cure. Best results are obtained when TORLON
parts are cured through a cycle of increasing temperature. Cure
cycle parameters are a function of the size and geometry of a
particular part.
Smooth taper
Material flow
Guidelines for Designing TORLON
Parts
TORLON polyamide-imide can be precision molded to fine
detail using a wide range of fabricating options. Not only can
the designer select a material with outstanding performance,
but one which gives him a great deal of design freedom.
The following sections provide guidelines for designing parts
with TORLON polyamide-imide.
Wall Section
Whenever feasible, wall thickness should be minimized within
the bounds prescribed by the end-use, to shorten cycle time
and economize on material. When sections must be molded to
thicknesses in excess of ½ inch (12.7 mm), parts may incorporate core and rib structures, or special TORLON grades may be
used.
For small parts molded with TORLON resin, wall sections generally range from 0.03-0.50 inch (0.8-13 mm), but thicknesses
up to 5 8 inch (19.0 mm) are possible with reinforced or bearing
grades.
TORLON polyamide-imide has a relatively high melt viscosity,
which limits flow length for a given wall thickness. Use of
hydraulic accumulators and precise process control reduce the
impact of this limitation. Many factors, such as part geometry,
flow direction, and severity of flow path changes make it difficult to characterize the relationship between flow length and
wall thickness for sections less than 0.050 inch (1.3 mm) thick.
We suggest you contact your Solvay Advanced Polymers Technical Representative to discuss the part under consideration.
Draft Angle
½° to 1° draft should be allowed to facilitate removal of the part
from the mold. With TORLON resin, draft angles as low as 1 8°
have been used, but such low angles require individual analysis.
Draft angle is also dependent on the depth of draw; the greater the
depth of draw, the greater the required draft angle (see Figure
54). Part complexity will also affect draft requirements, as will
the texture of the finish. A textured finish generally requires 1°
per side for every 0.001 inch (0.025 mm) of texture depth.
Figure 54
Draft
Dimensional Change Due to Draft
Depth of Draw
Wall Transition
Where it is necessary to vary wall thickness, gradual transition
is recommended to eliminate distortion and reduce internal
stresses. Figure 53 shows the desired method of transition -- a
smooth taper. It is better that the material flows from thick to
thin sections to avoid molding problems such as sinks and
voids.
Post-Curing TORLON Parts
– 38 –
Draft Angle
Solvay Advanced Polymers, L.L.C.
Cores
Coring is an effective way to reduce wall thickness in heavy
sections. To minimize mold cost, core removal should be parallel to the movement of the platens.
Draft should be added to core design. Blind cores should be
avoided, but if necessary, the general guidelines are: for cores
less than 3 16 inch (4.8 mm) diameter, the length should be no
greater than twice the diameter; if greater than 3 16 inch (4.8
mm), length should not exceed three times the diameter. For
cored-through holes, length should not exceed six times the
diameter for diameters over 3 16 inch (4.8 mm), and four times
the diameter for diameters less than 3 16 inch (4.8 mm).
Ribs
Ribs can increase the stiffness of TORLON parts without
increasing section thickness. The width of the rib at the base
should be equal the thickness of the adjacent wall to avoid
backfill. Ribs should be tapered for mold release.
Bosses
Bosses are commonly used to facilitate alignment during
assembly, but may serve other functions. In general, the outer
diameter of a boss should be equal to or greater than twice the
inside diameter of the hole, and the wall thickness of the boss
should be less than or equal to the adjacent wall thickness.
Table 36 defines the ratio of the wall thickness of polymer
around the insert to the outer diameter of the insert for common insert materials. Sufficient polymer surrounding the insert
is necessary for strength.
Threads
Threads can be molded-in. Both internal and external threads
can be molded using normal molding practices to Class 2 tolerance using TORLON resins. Class 3 can be molded using very
high precision tooling. In general, it is more economical to
machine threads for short runs. Table 39 on page 41 shows the
screw holding strength of TORLON threads.
Holes
Holes can serve a variety of functions. Electrical connectors, for
example, have numerous small holes in close proximity. Associated with each hole is a weld line which potentially is a weak
point. The degree of weakness is related to flow distance, part
geometry, and the thickness of the wall surrounding the hole.
Because TORLON resins can be molded to close tolerances,
and can be molded to thin cross sections without cracking,
they are excellent materials for this type of part; however, each
application must be considered on an individual basis due to
the complexity of design variables.
Undercuts
It is not possible to mold undercuts in TORLON parts unless
side pulls are used. To minimize mold costs, undercuts should
be avoided. If it is necessary, external undercuts can be
accommodated by use of a side pull, but internal undercuts
require collapsing or removable cores.
Molded-in inserts
Threads molded into TORLON parts have good pull-out
strength, but if greater strength is needed, metal inserts can be
molded-in. TORLON resins have low coefficients of thermal
expansion, making them excellent materials for applications
integrating plastic and metal. For ease of molding, inserts
should be situated perpendicular to the parting line and should
be supported so they are not displaced during injection of the
molten plastic. Inserts should be preheated to the temperature
of the mold.
Table 36
Wall Thickness/Insert O.D. Relationship
Insert material
Steel
Brass
Aluminum
TORLON PAI Design Guide
Ratio of wall thickness to insert o.d.
1.2
1.1
1.0
– 39 –
Holes
Secondary Operations
Joining
Table 37
TORLON parts can be joined mechanically or with adhesives.
Strength of HeliCoil Inserts
Tensile strength
Mechanical Joining Techniques
The dimensional stability and creep resistance of TORLON
polyamide-imide allows it to be readily joined with metal components even in rotating or sliding assemblies.
Snap-fit: Economical and Simple
Snap-fit is an economical and simple method of joining
TORLON parts. Although the strain limit must be considered for
a snap-fit assembly that will be repeatedly assembled and disassembled, TORLON engineering polymers are excellent for
this type of use, due to the superior fatigue strength of
polyamide-imide. The high modulus, elongation, and low creep
of TORLON resins also make them well suited for snap-fit
designs. Snap-in fingers in the locked position should be
strain-free, or under a level of stress which can be tolerated by
the material. TORLON resins can tolerate up to 10% strain for
the unfilled grades, and 5% strain for filled grades. Graphitefiber-reinforced grades are not suitable for snap-fit assembly.
Threaded Fasteners
Self-tapping Screws
In general, TORLON polyamide-imide is too tough for self-tapping screws. Tapped holes are recommended.
Molded-in Inserts
Metal inserts can be molded into TORLON parts. Preheating the
insert to the temperature of the mold is required for best
results. While polyamide-imide has low shrink, it is still important to have sufficient material around the insert to distribute
the stress induced by shrinkage.
Thread size
Engagement, in
mm
TORLON 4203L
lb-f
N
TORLON 5030
lb-f
N
#4-40
0.224
5.7
#6-32
0.276
7.0
#8-32
0.328
8.3
#10-32
0.380
9.6
¼"-20
0.500
12.7
870
3,870
1,470
6,540
1,840
8,180
2,200
9,790
2,830
12,600
970
4,310
1,700
7,560
2,140
9,520
2,940
13,100
5,200
23,100
Molded-in Threads
Both external and internal threads can be molded with TORLON
polymer to a Class 2 tolerance. Mating parts with metal fasteners in TORLON threads works well because the thermal expansion of TORLON polyamide-imide is close to that of metal, so
there is relatively low thermal stress at the metal-to-plastic
interface. Due to the increase in mold cost, it is generally advisable to machine threads for short runs.
Strength of Bolts made of TORLON Resin
Threaded fasteners molded from TORLON engineering polymers are dependable because of the high strength, modulus,
and load-bearing characteristics of TORLON engineering polymers. Bolts were injection molded from TORLON 4203L and
5030 then tested* for tensile strength, elongation, and torque
limit (Table 38). The bolts were 0.25 inch (6.3 mm) diameter,
type 28TPI with class 2A threads.
Table 38
Threaded Mechanical Inserts
Self-threading, self-locking inserts provide a high-strength,
low-stress option for joining TORLON parts. These metal inserts
have an exterior “locking” feature for anchorage in the
TORLON part and allow for repeated assembly and disassembly through the threaded interior. HeliCoil® inserts from HeliCoil
Products, division of Mite Corporation, and SpeedSerts® inserts
from Tridair Fasteners, Rexnord, Incorporated, are examples of
this type of insert.
Strength of TORLON Bolts
Tensile strength
TORLON 4203L
TORLON 5030
psi
18,200
18,400
MPa
125
127
Elongation
%
9.5
6.6
Shear torque
in-lb
28.6
27.2
N-m
3.2
3.1
*Tensile strength calculations were based on 0.0364 inch2 (0.235 cm2) cross sectioned area. Torque tests were conducted by tightening the bolts on a steel plate with
steel washers and nuts. Maximum shear torque was determined using a torque
wrench graduated in inch-pounds.
Table 37 gives the tensile strength of HeliCoil inserts in
TORLON 4203L and 5030. It is the axial force required to pull
the insert at least 0.020 inch (0.51 mm) out of TORLON
specimens .
Joining
– 40–
Solvay Advanced Polymers, L.L.C.
Screw Holding Strength
Metal screws can securely join threaded TORLON parts. Holes
for #4-40 screws were drilled and tapped in 0.19 inch (4.8
mm) thick TORLON plaques. Screw pull-out strength determined by ASTM D1761* appears in Table 39
Interference Fits
Interference, or press, fits provide joints with good strength at
minimum cost. TORLON engineering polymer is ideal for this
joining technique due to its resistance to creep. Diametrical
interference, actual service temperature, and load conditions
should be evaluated to determine if stresses are within design
limits.
Table 39
Screw Holding Strength of Threads in TORLON PAI
Pull-out strength
TORLON 4203L
TORLON 4275
TORLON 4301
lb
540
400
460
kg
240
180
200
Engagement
threads per hole
7.5
7.7
7.8
*Crosshead speed was 0.1 inch (2.5 mm) per minute. The span between the plaque
and the screw holding fixture was 1.08 inches (27 mm).
Ultrasonic Inserts
Metal inserts can be imbedded in uncured TORLON parts by
ultrasonic insertion. Inserts are installed rapidly with strength
comparable to that provided by molded-in techniques. A hole is
molded slightly smaller than the insert. The metal insert is
brought in contact with the TORLON part. Vibration in excess of
18 kHz is applied to the metal insert, creating frictional heat
which melts the plastic. High strength is achieved if sufficient
plastic flows around knurls, threads, etc.
Other Mechanical Joining Techniques
Because post-cured TORLON parts are extremely tough, some
joining techniques will not be suitable. Expansion inserts are
generally not recommended; however, each application should
be considered on an individual basis.
TORLON PAI Design Guide
– 41 –
Threaded Fasteners
Surface Preparation
Bonding with Adhesives
TORLON polyamide-imide parts can be joined with commercial
adhesives, extending design options. It is a good practice to
consult the adhesive supplier concerning the requirements of
your application.
Adhesive Choice
A variety of adhesives including amide-imide, epoxy, and
cyanoacrylate can be used to bond TORLON parts.
Cyanoacrylates have poor environmental resistance and are
not recommended. Silicone, acrylic, and urethane adhesives
are generally not recommended unless environment conditions
preclude other options. The amide-imide adhesive is made by
dissolving 35 parts of TORLON 4000T PAI powder in 65 parts of
N-methylpyrrolidone**.
**Warning! NMP is a flammable organic solvent and the appropriate handling procedures recommended by EPA, NIOSH, and OSHA should be followed. Adequate ventilation is necessary when using solvents.
Bonding surfaces should be free of contaminants, such as oil,
hydraulic fluid, and dust. TORLON parts should be dried for at
least 24 hours at 300°F (149°C) In a desiccant oven (thicker
parts, over ¼ inch (6.3 mm), require longer drying time) to dispel casual moisture prior to bonding. TORLON surfaces should
be mechanically abraded and solvent-wiped, or treated with a
plasma arc to enhance adhesion.
Adhesive Application
For adhesives other than amide-imide, follow the manufacturer’s directions. For amide-imide adhesive: coat each of the
mating surfaces with a thin, uniform film of the adhesive.
Adhesive-coated surfaces should be clamped under minimal
pressure, approximately 0.25 psi (1.7 Pa) . The excess adhesive can be cleaned with N-methylpyrrolidone (NMP).**
**Warning! NMP is a flammable organic solvent and the appropriate handling procedures recommended by EPA, NIOSH, and OSHA should be followed. Adequate ventilation is necessary when using solvents.
TORLON PAI Grade
Curing Procedure
TORLON resin grades 4203L, 5030, and 7130 are relatively
easy to bond. Bearing grades 4301, 4275, and 4435 have
inherent lubricity, and are more difficult to bond. Table 40 compares the shear strengths of these grades bonded with epoxy,
cyanoacrylate, and amide-imide adhesives.
Amide-imide adhesive should be cured in a vented, air-circulating oven. The recommended cycle is 24 hours at 73°F, 24
hours at 300°F, 2 hours at 400°F. The parts should remain
clamped until cooled to below 150°F (66°C).
Post-cured TORLON bars, 2.5 x 0.5 x 0.125 inch (64 x 13 x 3
mm) were lightly abraded, wiped with acetone, then bonded
with a 0.5 inch (13 mm) overlap. The clamped parts were
cured per the adhesive manufacturer’s recommendations. After
seven days at room temperature, bonds were pulled apart with
a tensile testing machine at a crosshead speed of 0.05 inches
per minute (1.3 mm per minute). If failure occurred outside the
bond area, the process was repeated with progressively
smaller bond areas, to a minimum overlap of 0.125 inch (3.2
mm).
Commercial adhesives were used to bond TORLON parts. The
bonds were evaluated for shear strength, which appears in
Table 40.
Method of cure, handling, and working life of the adhesive are
rated in terms of “ease of use” Useful temperature ranges
appear in the manufacturers’ literature and will vary with factors such as load and chemical environment.
Epoxy(1)
Cyanoacrylate
PAI Grade
TORLON 4203L
TORLON 4301
TORLON 4275
TORLON 5030
TORLON 7130
Ease of use 1= easiest
Useful temperature range,
°F
°C
Bond Strength of Various Adhesives
psi
6,000+
2,250
3,500
4,780
6,400+
(2)
MPa
41.4
15.5
24.1
33.0
44.1
psi
2,780
1,740
1,680
3,070
3,980
MPa
19.2
12.0
11.6
21.2
27.4
Amide-imide
psi
5,000+
2,890
3,400
5,140
4,750
MPa
34.5
19.9
23.4
35.4
32.8
2
1
3
- 67 to 160
- 55 to 71
- 20 to 210
- 29 to 99
- 321 to 500
- 196 to 260
(1) Hysol EA 9 30. Hysol is a trademark of Dexter Corporation.
(2)
Joining
– 42–
Solvay Advanced Polymers, L.L.C.
Bonding TORLON Parts to Metal
TORLON and metal parts can be joined with adhesives. With
proper surface preparation and adhesive handling, the resulting
bonds will have high strength. In addition, there will be minimal
stress at the interface with temperature change. This is
because TORLON resins, unlike many other high temperature
plastics, have expansion coefficients similar to those of metals.
As mentioned in the preceding section, bond strength depends
on adhesive selection, and TORLON grade, as well as proper
technique in preparing and curing the bond. Table 41 reports
shear strength data for TORLON PAI to aluminum and TORLON
PAI to steel bonds. Mechanical abrasion alone may not be adequate for preparing steel surfaces — chemical treatment of the
steel is recommended when service temperature requires the
use of amide-imide adhesive.
Table 41
Shear Strength of TORLON PAI to Metal Bonds
Shear Strength—Aluminum 2024 to TORLON PAI Bonds
Epoxy(1)
TORLON 4203L
TORLON 4301
TORLON 4275
TORLON 5030
TORLON 7130
psi
4000
2500
2450
3900
4000
Cyanoacrylate(2)
MPa
27.6
17.2
16.9
26.9
27.6
psi
1350
1450
750
3250
3750
MPa
9.3
10.0
5.2
22.4
25.9
Amide-imide
psi
5050+
4950+
4350+
6050+
6400+
MPa
34.8+
34.1+
30.0+
41.7+
44.1+
Shear Strength—Cold Rolled Steel to TORLON PAI Bonds
Epoxy(1)
TORLON 4203L
TORLON 4301
TORLON 4275
TORLON 5030
TORLON 7130
psi
3050
3700
3150
4650
4550
MPa
21.0
25.5
21.7
32.1
31.4
Ease of use 1= easiest
Useful temperature range,
°F
°C
Cyanoacrylate(2)
psi
2200
2050
2450
2100
2450
MPa
15.2
14.1
16.9
14.5
16.9
Amide-imide
psi
1450
1850
1900
2400
1100
MPa
10.0
12.7
13.1
16.5
7.6
2
1
3
- 67 to 160
-55 to 71
- 20 to 210
- 29 to 99
- 321 to 500
- 196 to 260
*This test used TORLON bars 2.5 x 0.5 x 0.125 inches (64 x 13 x 3 mm); steel strips of similar size were cut from cold rolled steel, dull finished panel; and aluminum strips were cut
from 2024 alloy panels.
(1) Hysol EA 9330. Hysol is a trademark of Dexter Corporation.
(2) CA 5000. Lord Corporation.
TORLON PAI Design Guide
– 43 –
Bonding with Adhesives
Guidelines for Machining Parts
Made From TORLON Resin
Table 42
Molded shapes and extruded bars manufactured from TORLON
polyamide-imide can be machined using the same techniques
normally used for machining mild steel or acrylics. Machining
parameters for several typical operations are presented in
Table 42.
Turning
Cutting speed, fpm
Feed, in/rev
Relief angle, degrees
Rake angle, degrees
Cutting depth, in
300-800
0.004-0.025
5-15
7-15
0.025
Circular Sawing
Cutting, fpm
Feed, in/rev
Relief angle, degrees
Set
Rake angle, degrees
6000-8000
fast & steady
15
slight
15
Milling
Cutting speed, fpm
Feed, in/rev
Relief angle, degrees
Rake angle, degrees
Cutting depth, in
500-800
0.006-0.035
5-15
7-15
0.035
Drilling
Cutting speed, rpm
Feed, in/rev
Relief angle, degrees
Point angle, degrees
300-800
0.003-0.015
0
118
Reaming
Slow speed, rpm
150
Guidelines for Machining Parts Made From TORLON
Resin
Parts made from TORLON resin are dimensionally stable, and
do not deflect or yield as the cutting tool makes its pass. All
TORLON grades are very abrasive to standard tools, and
high-speed tools should not be used.
Carbide-tipped tools may be used, but diamond-tipped or insert
cutting tools are strongly recommended. These tools will outlast carbide-tipped tools and provide a strong economic incentive for production operations, despite a relatively high initial
cost. Thin sections or sharp corners must be worked with care
to prevent breakage and chipping. Damage to fragile parts can
be minimized by using shallow cuts during finishing operations.
The use of mist coolants to cool the tool tip and to help remove
chips or shavings from the work surface is recommended. Air
jets or vacuum can be used to keep the work surface clean.
Parts machined from injection-molded blanks may have built-in
stresses. To minimize distortion, parts should be machined
symmetrically, to relieve opposing stresses.
Machined Parts Should be Recured.
Parts designed for friction and wear-intensive service, or which
will be subjected to harsh chemical environments, should be
recured after machining to insure optimum performance. If
such a part has been machined to greater than 116 inch (1.6
mm) depth, recuring is strongly recommended.
Guidelines for Machining Parts Made From TORLON Resin
– 44 –
Solvay Advanced Polymers, L.L.C.
Technical Service
Our expert technical staff is ready to answer your questions
related to designing, molding, finishing or testing TORLON
parts. We respect proprietary information and will consult with
you on a confidential basis.
The latest design, fabrication, and testing equipment available
to our service engineers supplements their years of practical
experience with applications of TORLON polymers. Using a
computer-aided design workstation, our engineers can forecast
the cost and performance of your proposed part and offer suggestions for efficient molding. Solvay Advanced Polymers can
also provide rod, sheet, film, plate, ball, disc, and tube stock
shapes for making prototype parts.
The availability of these services can be a tremendous help as
you evaluate TORLON polyamide-imide for your engineering
resin needs.
Whatever type of process you are considering, our personnel
and facilities can help you achieve consistent quality and more
profitable products. Call us to discuss your ideas.
TORLON PAI Design Guide
– 45 –
Bonding with Adhesives
Index
!
20 MM Vertical Burn Test · · · · · · · · · · · 17
A
Absorption Rate · · · · · · · · · · · · · · · · 21
Adhesive · · · · · · · · · · · · · · · 42 - 43,45
Aluminum alloy · · · · · · · · · · · · · · · · 13
Aluminum alloys · · · · · · · · · · · · · · · 33
ASTM D 5204 · · · · · · · · · · · · · · · · 32
ASTM D 638 · · · · · · · · · · · · · · · · · · 7
Automotive· · · · · · · · · · · · · · · · · 20,32
Aviation Fluids · · · · · · · · · · · · · · · · 20
B
Bearing Design · · · · ·
Bearing Shaft Clearance·
Bond Strength· · · · · ·
Bonding· · · · · · · · ·
Bosses · · · · · · · · ·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
· · · · 26
· · · · 31
· · · · 42
42 - 43,45
· · · · 39
C
Carbon Steel · · · · · · · · · · · · · · · · · 33
carbon steel · · · · · · · · · · · · · · · · · 13
Chemical Resistance · · · · · · · · · · · 19 - 20
Chemical Resistance Under Stress · · · · · · 20
Chemical structure · · · · · · · · · · · · · · · 1
Clearance · · · · · · · · · · · · · · · · · · · 31
CLTE · · · · · · · · · · · · · · · · · · · · · 13
Coefficient of Linear Thermal Expansion · · 4 - 5
Compression Molding · · · · · · · · · · · · · 37
Compressive Modulus · · · · · · · · · · · 4 - 5
Compressive Strength · · · · · · · · · · · 4 - 5
Constant Humidity· · · · · · · · · · · · · · · 21
Copper · · · · · · · · · · · · · · · · · · · · 13
Cores · · · · · · · · · · · · · · · · · · · · · 39
Creep Resistance· · · · · · · · · · · · · 14 - 15
D
D 638· · · · · · · · · · · · · · · · · · · · · · 7
Deflection Temperature· · · · · · · · · · · · · 4
Density · · · · · · · · · · · · · · · · · · · 4 - 5
Designing · · · · · · · · · · · · · · · · 37 - 38
Dielectric constant · · · · · · · · · · · · · · · 4
Dielectric Constant · · · · · · · · · · · · · · · 5
Dielectric Strength · · · · · · · · · · · · · · · 5
Dielectric strength · · · · · · · · · · · · · · · 4
Dimensional Changes · · · · · · · · · · · · · 22
Dissipation factor · · · · · · · · · · · · · · · · 4
Dissipation Factor · · · · · · · · · · · · · · · 5
Draft Angle · · · · · · · · · · · · · · · · · · 38
E
Effects of Water · · · · · · · · · · · · · · 21,23
Electrical Properties · · · · · · · · · · · · 22,25
Extrusion · · · · · · · · · · · · · · · · · · · 37
F
FAA Flammability · · · · · · · · · · · · · · · 18
Fabrication · · · · · · · · · · · · · · · · · · 37
Fasteners · · · · · · · · · · · · · · · · 40 - 41
Fatigue Strength · · · · · · · · · · · · · · · · 9
Flammability · · · · · · · · · 4 - 5,13,16 - 18,32
Flexural Modulus · · · · · · · · · · · · · 4 - 5,7
High Temperature
7
Low Temperature
7
Flexural Strength · · · · · · · · · · · · · · 4 - 6
High Temperature
6
Low Temperature
7
Fracture Toughness · · · · · · · · · · · · · · 11
Friction and Wear · · · · · · · · · · 26,28,30,32
G
Gamma Radiation · · · · · · · · · · · · · · · 24
Geometry and Load Considerations · · · · 34,36
Grades · · · · · · · · · · · · · · · · · · 2 - 3,5
H
Heat Deflection Temperature · · · · · · · · 4 - 5
Holes · · · · · · · · · · · · · · · · · · · 39,41
Horizontal Burning Test · · · · · · · · · · · · 17
I
Ignition Properties · · · · · · · · · · · · 16 - 17
Impact Resistance· · · · · · · · · · · · · · · 10
Impact Strength· · · · · · · · · · · · · · · 4 - 5
Industry and Agency Approvals · · · · · · · · 32
Injection Molding · · · · · · · · · · · · · · · 37
inserts · · · · · · · · · · · · · · · · · · 39 - 41
Interference Fits· · · · · · · · · · · · · · · · 41
Introduction · · · · · · · · · · · · · · · · · 1,26
Izod Impact Strength · · · · · · · · · · · · 4 - 5
J
Joining · · · · · · · · · · · · · · · · · · 40 - 42
L
Lubricated Wear Resistance· · · · · · · · · · 29
M
Machining· · · · · · · · · · · · · · · · · · · 44
Magnesium · · · · · · · · · · · · · · · · · · 33
Material Efficiency · · · · · · · · · · · · · · 33
Mating Surface · · · · · · · · · · · · · · · · 29
Maximum Working Stresses· · · · · · · · · · 36
Mechanical Joining· · · · · · · · · · · · 40 - 41
Mechanical Properties · · · · · · · · · · · · 6,8
Military Specification · · · · · · · · · · · · · 32
Molded-in Inserts · · · · · · · · · · · · · · · 40
N
National Aeronautics and Space Administration 32
NBS Smoke Density · · · · · · · · · · · · · · 16
O
S
Secondary Operations · · · · · · · · · · · · · 40
Self-tapping Screws· · · · · · · · · · · · · · 40
Shear Strength · · · · · · · · · · · · · · · 4 - 5
Snap-fit · · · · · · · · · · · · · · · · · · · · 40
Society of Automotive Engineers · · · · · · · 32
Specific Heat · · · · · · · · · · · · · · · · · 13
Specific Modulus · · · · · · · · · · · · · · · 33
Specific Strength · · · · · · · · · · · · · · · 33
Stainless steel · · · · · · · · · · · · · · · 13,33
Stress Concentration · · · · · · · · · · · · · 35
Stress-Strain Relationship · · · · · · · · · · · 8
Structural Design · · · · · · · · · · · · · · · 33
Surface resistivity · · · · · · · · · · · · · · · 4
Surface Resistivity · · · · · · · · · · · · · · · 5
T
Technical Service · · · · · · · · · · · · · · · 45
Tensile Elongation · · · · · · · · · · · · · 4 - 5
Tensile Modulus · · · · · · · · · · · · · · 4 - 5
Tensile Properties · · · · · · · · · · · · · · · 7
Tensile Strength · · · · · · · · · · · 4 - 7,20,24
High Temperature
6
Low Temperature
7
TGA · · · · · · · · · · · · · · · · · · · · · · 12
Thermal Aging · · · · · · · · · · · · · · · · 12
Thermal Conductivity · · · · · · · · · · 4 - 5,13
Thermal Shock · · · · · · · · · · · · · · · · 23
Thermal Stability· · · · · · · · · · · · · · 12,14
Thermogravimetric Analysis · · · · · · · · · · 12
Threads · · · · · · · · · · · · · · · · · 39 - 41
Thrust Washer· · · · · · · · · · · · · · · · · 26
Titanium · · · · · · · · · · · · · · · · · · 13,33
Toxic Gas Emission Test· · · · · · · · · · · · 16
Typical Properties · · · · · · · · · · · · · · · 4
SI Units
5
US Units
4
U
UL 57 · · · · · · · · · · · · · · · · · · · · · 18
UL 94 · · · · · · · · · · · · · · · · · · · 13,17
UL Relative Thermal Index· · · · · · · · · · · 12
Ultrasonic Inserts · · · · · · · · · · · · · · · 41
Undercuts · · · · · · · · · · · · · · · · · · · 39
Underwriters’ Laboratories · · · · · · · · · · 32
V
Oxygen Index · · · · · · · · · · · · · · 4 - 5,16
Volume resistivity· · · · · · · · · · · · · · · · 4
Volume Resistivity · · · · · · · · · · · · · · · 5
P
W
Performance Properties· · · · · · · · · · · · · 6
Physical Properties · · · · · · · · · · · · · 3 - 4
Poisson’s Ratio · · · · · · · · · · · · · · · 4 - 5
Post-curing · · · · · · · · · · · · · · · · · · 38
PV Limit · · · · · · · · · · · · · · · · · · · 27
Wall Section· · · · · · · · · · · · · · · · · · 38
Wall Transition · · · · · · · · · · · · · · · · 38
Water absorption · · · · · · · · · · · · · · · · 4
Water Absorption · · · · · · · · · · · · · · · · 5
Wear Factor · · · · · · · · · · · · · · · · · · 28
Wear Rate · · · · · · · · · · · · · · · · · · · 28
Wear Resistance and Post-Cure · · · · · · · · 30
Wear Resistant · · · · · · · · · · · · · · · · · 1
Wear Resistant Grades · · · · · · · · · · · · 26
Weather-Ometer Testing · · · · · · · · · · · 24
R
Relative Thermal Index · · · · · · · · · · · · 12
Resistance To Cyclic Stress · · · · · · · · 9 - 10
Ribs · · · · · · · · · · · · · · · · · · · · · · 39
Rockwell hardness · · · · · · · · · · · · · · · 4
Rockwell Hardness · · · · · · · · · · · · · · · 5
RTI · · · · · · · · · · · · · · · · · · · · · · 12
Centrifugal Compressor
Labyrinth Seals
TORLON® polyamide-imide resins produce
labyrinth seals that are more corrosion
resistant than Aluminum and can be fitted to
smaller clearances. Smaller clearances mean
higher efficiency and greater through-put
without increasing energy input. Better
corrosion resistance means more productive
time between maintenance shutdowns.
Automotive Drivetrain
Thrust Washers
TORLON® polyamide-imide resin
drive train thrust washers in
automotive applications have
superior impact strength, wear
resistance, and chemical
resistance.
Diesel Engine Thrust Washers
TORLON® polyamide-imide thrust washers
absorb and dissipate impact energy in truck
engines. They offer low friction and wear, high
pressure and velocity limits, excellent
mechanical properties and heat resistance.
TORLON
Solvay Advanced Polymers, L.L.C.
4500 McGinnis Ferry Road
Alpharetta, GA 30005-3914
USA
Phone: +1.770.772.8200
+1.800.621.4557 (U.S. only)
Fax:
+1.770.772.8454
Solvay Advanced Polymers, L.L.C. and its affiliates have offices in
the Americas, Europe, and Asia. Please visit our website at
www.solvayadvancedpolymers.com to locate the office nearest to you.
Product and Technical Literature
To our actual knowledge, the information contained herein is accurate
as of the date of this document. However, neither Solvay Advanced
Polymers, L.L.C. nor any of its affiliates makes any warranty, express
or implied, or accepts any liability in connection with this information
or its use. This information is for use by technically skilled persons at
their own discretion and risk and does not relate to the use of this
product in combination with any other substance or any other
process. This is not a license under any patent or other proprietary
right. The user alone must finally determine suitability of any information or material for any contemplated use, the manner of use and
whether any patents are infringed.
Health and Safety Information
Material Safety Data Sheets (MSDS) for products of Solvay Advanced
Polymers are available upon request from your sales representative or
by writing to the address shown on this document. The appropriate
MSDS should be consulted before using any of our products.
TORLON is a registered trademark of Solvay Advanced Polymers, L.L.C.
T-50246
© 2003 Solvay Advanced Polymers, L.L.C. All rights reserved.
D 08/03
design
®
TORLON
Polyamide-imide
Design Guide